diff --git a/SysML2.NET.Tests/Extend/AcceptActionUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/AcceptActionUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..54896dc4
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/AcceptActionUsageExtensionsTestFixture.cs
@@ -0,0 +1,50 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Actions;
+
+ [TestFixture]
+ public class AcceptActionUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputePayloadArgument_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAcceptActionUsage)null).ComputePayloadArgument());
+ }
+
+ [Test]
+ public void ComputePayloadParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAcceptActionUsage)null).ComputePayloadParameter());
+ }
+
+ [Test]
+ public void ComputeReceiverArgument_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAcceptActionUsage)null).ComputeReceiverArgument());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ActionDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ActionDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..e9b23b70
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ActionDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Actions;
+
+ [TestFixture]
+ public class ActionDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IActionDefinition)null).ComputeAction());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ActionUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ActionUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..0511dd96
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ActionUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Actions;
+
+ [TestFixture]
+ public class ActionUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeActionDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IActionUsage)null).ComputeActionDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ActorMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ActorMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..17d6067f
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ActorMembershipExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Requirements;
+
+ [TestFixture]
+ public class ActorMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwnedActorParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IActorMembership)null).ComputeOwnedActorParameter());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/AllocationDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/AllocationDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..c36804c0
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/AllocationDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Allocations;
+
+ [TestFixture]
+ public class AllocationDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeAllocation_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAllocationDefinition)null).ComputeAllocation());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/AllocationUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/AllocationUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..0fbc2e93
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/AllocationUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Allocations;
+
+ [TestFixture]
+ public class AllocationUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeAllocationDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAllocationUsage)null).ComputeAllocationDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/AnalysisCaseDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/AnalysisCaseDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..f3e695f3
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/AnalysisCaseDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.AnalysisCases;
+
+ [TestFixture]
+ public class AnalysisCaseDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeResultExpression_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAnalysisCaseDefinition)null).ComputeResultExpression());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/AnalysisCaseUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/AnalysisCaseUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..296d0351
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/AnalysisCaseUsageExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.AnalysisCases;
+
+ [TestFixture]
+ public class AnalysisCaseUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeAnalysisCaseDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAnalysisCaseUsage)null).ComputeAnalysisCaseDefinition());
+ }
+
+ [Test]
+ public void ComputeResultExpression_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAnalysisCaseUsage)null).ComputeResultExpression());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/AnnotatingElementExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/AnnotatingElementExtensionsTestFixture.cs
new file mode 100644
index 00000000..d554db0b
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/AnnotatingElementExtensionsTestFixture.cs
@@ -0,0 +1,56 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Root.Annotations;
+
+ [TestFixture]
+ public class AnnotatingElementExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeAnnotatedElement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAnnotatingElement)null).ComputeAnnotatedElement());
+ }
+
+ [Test]
+ public void ComputeAnnotation_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAnnotatingElement)null).ComputeAnnotation());
+ }
+
+ [Test]
+ public void ComputeOwnedAnnotatingRelationship_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAnnotatingElement)null).ComputeOwnedAnnotatingRelationship());
+ }
+
+ [Test]
+ public void ComputeOwningAnnotatingRelationship_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAnnotatingElement)null).ComputeOwningAnnotatingRelationship());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/AnnotationExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/AnnotationExtensionsTestFixture.cs
new file mode 100644
index 00000000..b6bba233
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/AnnotationExtensionsTestFixture.cs
@@ -0,0 +1,56 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Root.Annotations;
+
+ [TestFixture]
+ public class AnnotationExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeAnnotatingElement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAnnotation)null).ComputeAnnotatingElement());
+ }
+
+ [Test]
+ public void ComputeOwnedAnnotatingElement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAnnotation)null).ComputeOwnedAnnotatingElement());
+ }
+
+ [Test]
+ public void ComputeOwningAnnotatedElement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAnnotation)null).ComputeOwningAnnotatedElement());
+ }
+
+ [Test]
+ public void ComputeOwningAnnotatingElement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAnnotation)null).ComputeOwningAnnotatingElement());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/AssertConstraintUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/AssertConstraintUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..8e26c6cc
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/AssertConstraintUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Constraints ;
+
+ [TestFixture]
+ public class AssertConstraintUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeAssertedConstraint_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAssertConstraintUsage)null).ComputeAssertedConstraint());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/AssignmentActionUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/AssignmentActionUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..898659d9
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/AssignmentActionUsageExtensionsTestFixture.cs
@@ -0,0 +1,50 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Actions;
+
+ [TestFixture]
+ public class AssignmentActionUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeReferent_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAssignmentActionUsage)null).ComputeReferent());
+ }
+
+ [Test]
+ public void ComputeTargetArgument_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAssignmentActionUsage)null).ComputeTargetArgument());
+ }
+
+ [Test]
+ public void ComputeValueExpression_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAssignmentActionUsage)null).ComputeValueExpression());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/AssociationExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/AssociationExtensionsTestFixture.cs
new file mode 100644
index 00000000..9a7f4bc6
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/AssociationExtensionsTestFixture.cs
@@ -0,0 +1,56 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Associations;
+
+ [TestFixture]
+ public class AssociationExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeAssociationEnd_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAssociation)null).ComputeAssociationEnd());
+ }
+
+ [Test]
+ public void ComputeRelatedType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAssociation)null).ComputeRelatedType());
+ }
+
+ [Test]
+ public void ComputeSourceType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAssociation)null).ComputeSourceType());
+ }
+
+ [Test]
+ public void ComputeTargetType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAssociation)null).ComputeTargetType());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/AttributeUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/AttributeUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..a5a50db5
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/AttributeUsageExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Attributes ;
+
+ [TestFixture]
+ public class AttributeUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeAttributeDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAttributeUsage)null).ComputeAttributeDefinition());
+ }
+
+ [Test]
+ public void ComputeIsReference_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IAttributeUsage)null).ComputeIsReference());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/BehaviorExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/BehaviorExtensionsTestFixture.cs
new file mode 100644
index 00000000..02ac7670
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/BehaviorExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Behaviors;
+
+ [TestFixture]
+ public class BehaviorExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IBehavior)null).ComputeParameter());
+ }
+
+ [Test]
+ public void ComputeStep_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IBehavior)null).ComputeStep());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/BooleanExpressionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/BooleanExpressionExtensionsTestFixture.cs
new file mode 100644
index 00000000..699ca3ec
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/BooleanExpressionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Functions ;
+
+ [TestFixture]
+ public class BooleanExpressionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputePredicate_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IBooleanExpression)null).ComputePredicate());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/CalculationDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/CalculationDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..f574cf02
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/CalculationDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Calculations;
+
+ [TestFixture]
+ public class CalculationDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeCalculation_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ICalculationDefinition)null).ComputeCalculation());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/CalculationUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/CalculationUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..5767e8a8
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/CalculationUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Calculations ;
+
+ [TestFixture]
+ public class CalculationUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeCalculationDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ICalculationUsage)null).ComputeCalculationDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/CaseDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/CaseDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..a9bedfd4
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/CaseDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,50 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Cases ;
+
+ [TestFixture]
+ public class CaseDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeActorParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ICaseDefinition)null).ComputeActorParameter());
+ }
+
+ [Test]
+ public void ComputeObjectiveRequirement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ICaseDefinition)null).ComputeObjectiveRequirement());
+ }
+
+ [Test]
+ public void ComputeSubjectParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ICaseDefinition)null).ComputeSubjectParameter());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/CaseUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/CaseUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..d09a2ffe
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/CaseUsageExtensionsTestFixture.cs
@@ -0,0 +1,56 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Cases;
+
+ [TestFixture]
+ public class CaseUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeActorParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ICaseUsage)null).ComputeActorParameter());
+ }
+
+ [Test]
+ public void ComputeCaseDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ICaseUsage)null).ComputeCaseDefinition());
+ }
+
+ [Test]
+ public void ComputeObjectiveRequirement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ICaseUsage)null).ComputeObjectiveRequirement());
+ }
+
+ [Test]
+ public void ComputeSubjectParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ICaseUsage)null).ComputeSubjectParameter());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ClassifierExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ClassifierExtensionsTestFixture.cs
new file mode 100644
index 00000000..4695a989
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ClassifierExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Classifiers;
+
+ [TestFixture]
+ public class ClassifierExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwnedSubclassification_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IClassifier)null).ComputeOwnedSubclassification());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ConcernUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ConcernUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..1aa0ff0b
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ConcernUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Requirements;
+
+ [TestFixture]
+ public class ConcernUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeConcernDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConcernUsage)null).ComputeConcernDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ConjugatedPortDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ConjugatedPortDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..99b4285c
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ConjugatedPortDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Ports;
+
+ [TestFixture]
+ public class ConjugatedPortDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOriginalPortDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConjugatedPortDefinition)null).ComputeOriginalPortDefinition());
+ }
+
+ [Test]
+ public void ComputeOwnedPortConjugator_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConjugatedPortDefinition)null).ComputeOwnedPortConjugator());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ConjugatedPortTypingExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ConjugatedPortTypingExtensionsTestFixture.cs
new file mode 100644
index 00000000..66c2dbd5
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ConjugatedPortTypingExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Ports;
+
+ [TestFixture]
+ public class ConjugatedPortTypingExtensionsTestFixture
+ {
+ [Test]
+ public void ComputePortDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConjugatedPortTyping)null).ComputePortDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ConjugationExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ConjugationExtensionsTestFixture.cs
new file mode 100644
index 00000000..0c9481ef
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ConjugationExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Types;
+
+ [TestFixture]
+ public class ConjugationExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwningType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConjugation)null).ComputeOwningType());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ConnectionDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ConnectionDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..2dbd5578
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ConnectionDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Connections;
+
+ [TestFixture]
+ public class ConnectionDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeConnectionEnd_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConnectionDefinition)null).ComputeConnectionEnd());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ConnectionUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ConnectionUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..9ae8a147
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ConnectionUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Connections;
+
+ [TestFixture]
+ public class ConnectionUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeConnectionDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConnectionUsage)null).ComputeConnectionDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ConnectorExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ConnectorExtensionsTestFixture.cs
new file mode 100644
index 00000000..e1cf2601
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ConnectorExtensionsTestFixture.cs
@@ -0,0 +1,68 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Connectors;
+
+ [TestFixture]
+ public class ConnectorExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeAssociation_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConnector)null).ComputeAssociation());
+ }
+
+ [Test]
+ public void ComputeConnectorEnd_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConnector)null).ComputeConnectorEnd());
+ }
+
+ [Test]
+ public void ComputeDefaultFeaturingType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConnector)null).ComputeDefaultFeaturingType());
+ }
+
+ [Test]
+ public void ComputeRelatedFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConnector)null).ComputeRelatedFeature());
+ }
+
+ [Test]
+ public void ComputeSourceFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConnector)null).ComputeSourceFeature());
+ }
+
+ [Test]
+ public void ComputeTargetFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConnector)null).ComputeTargetFeature());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ConstraintUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ConstraintUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..d8d4f61f
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ConstraintUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Constraints;
+
+ [TestFixture]
+ public class ConstraintUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeConstraintDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IConstraintUsage)null).ComputeConstraintDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/CrossSubsettingExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/CrossSubsettingExtensionsTestFixture.cs
new file mode 100644
index 00000000..a93a9731
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/CrossSubsettingExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Features;
+
+ [TestFixture]
+ public class CrossSubsettingExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeCrossingFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ICrossSubsetting)null).ComputeCrossingFeature());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/DefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/DefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..f9998101
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/DefinitionExtensionsTestFixture.cs
@@ -0,0 +1,219 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.DefinitionAndUsage;
+
+ [TestFixture]
+ public class DefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeDirectedUsage_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeDirectedUsage());
+ }
+
+ [Test]
+ public void ComputeOwnedAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedAction());
+ }
+
+ [Test]
+ public void ComputeOwnedAllocation_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedAllocation());
+ }
+
+ [Test]
+ public void ComputeOwnedAnalysisCase_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedAnalysisCase());
+ }
+
+ [Test]
+ public void ComputeOwnedAttribute_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedAttribute());
+ }
+
+ [Test]
+ public void ComputeOwnedCalculation_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedCalculation());
+ }
+
+ [Test]
+ public void ComputeOwnedCase_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedCase());
+ }
+
+ [Test]
+ public void ComputeOwnedConcern_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedConcern());
+ }
+
+ [Test]
+ public void ComputeOwnedConnection_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedConnection());
+ }
+
+
+ [Test]
+ public void ComputeOwnedConstraint_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedConstraint());
+ }
+
+ [Test]
+ public void ComputeOwnedEnumeration_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedEnumeration());
+ }
+
+ [Test]
+ public void ComputeOwnedFlow_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedFlow());
+ }
+
+ [Test]
+ public void ComputeOwnedInterface_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedInterface());
+ }
+
+ [Test]
+ public void ComputeOwnedItem_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedItem());
+ }
+
+ [Test]
+ public void ComputeOwnedMetadata_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedMetadata());
+ }
+
+ [Test]
+ public void ComputeOwnedOccurrence_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedOccurrence());
+ }
+
+ [Test]
+ public void ComputeOwnedPart_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedPart());
+ }
+
+ [Test]
+ public void ComputeOwnedPort_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedPort());
+ }
+
+ [Test]
+ public void ComputeOwnedReference_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedReference());
+ }
+
+ [Test]
+ public void ComputeOwnedRendering_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedRendering());
+ }
+
+ [Test]
+ public void ComputeOwnedRequirement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedRequirement());
+ }
+
+ [Test]
+ public void ComputeOwnedState_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedState());
+ }
+
+ [Test]
+ public void ComputeOwnedTransition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedTransition());
+ }
+
+ [Test]
+ public void ComputeOwnedUsage_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedUsage());
+ }
+
+ [Test]
+ public void ComputeOwnedUseCase_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedUseCase());
+ }
+
+ [Test]
+ public void ComputeOwnedVerificationCase_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedVerificationCase());
+ }
+
+ [Test]
+ public void ComputeOwnedView_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedView());
+ }
+
+ [Test]
+ public void ComputeOwnedViewpoint_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeOwnedViewpoint());
+ }
+
+ [Test]
+ public void ComputeUsage_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeUsage());
+ }
+
+ [Test]
+ public void ComputeVariant_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeVariant());
+ }
+
+ [Test]
+ public void ComputeVariantMembership_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDefinition)null).ComputeVariantMembership());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/DifferencingExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/DifferencingExtensionsTestFixture.cs
new file mode 100644
index 00000000..948f4681
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/DifferencingExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Types;
+
+ [TestFixture]
+ public class DifferencingExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeTypeDifferenced_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDifferencing)null).ComputeTypeDifferenced());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/DisjoiningExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/DisjoiningExtensionsTestFixture.cs
new file mode 100644
index 00000000..d4b0c0f8
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/DisjoiningExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Types;
+
+ [TestFixture]
+ public class DisjoiningExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwningType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDisjoining)null).ComputeOwningType());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/DocumentationExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/DocumentationExtensionsTestFixture.cs
new file mode 100644
index 00000000..8d248cbb
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/DocumentationExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Root.Annotations;
+
+ [TestFixture]
+ public class DocumentationExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeDocumentedElement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IDocumentation)null).ComputeDocumentedElement());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ElementExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ElementExtensionsTestFixture.cs
new file mode 100644
index 00000000..df68e44d
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ElementExtensionsTestFixture.cs
@@ -0,0 +1,98 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Root.Elements;
+
+ [TestFixture]
+ public class ElementExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeDocumentation_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IElement)null).ComputeDocumentation());
+ }
+
+ [Test]
+ public void ComputeIsLibraryElement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IElement)null).ComputeIsLibraryElement());
+ }
+
+ [Test]
+ public void ComputeName_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IElement)null).ComputeName());
+ }
+
+ [Test]
+ public void ComputeOwnedAnnotation_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IElement)null).ComputeOwnedAnnotation());
+ }
+
+ [Test]
+ public void ComputeOwnedElement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IElement)null).ComputeOwnedElement());
+ }
+
+ [Test]
+ public void ComputeOwner_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IElement)null).ComputeOwner());
+ }
+
+ [Test]
+ public void ComputeOwningMembership_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IElement)null).ComputeOwningMembership());
+ }
+
+ [Test]
+ public void ComputeOwningNamespace_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IElement)null).ComputeOwningNamespace());
+ }
+
+ [Test]
+ public void ComputeQualifiedName_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IElement)null).ComputeQualifiedName());
+ }
+
+ [Test]
+ public void ComputeShortName_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IElement)null).ComputeShortName());
+ }
+
+ [Test]
+ public void ComputeTextualRepresentation_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IElement)null).ComputeTextualRepresentation());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ElementFilterMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ElementFilterMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..82bb41d8
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ElementFilterMembershipExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Packages;
+
+ [TestFixture]
+ public class ElementFilterMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeCondition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IElementFilterMembership)null).ComputeCondition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/EndFeatureMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/EndFeatureMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..579043b4
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/EndFeatureMembershipExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Features;
+
+ [TestFixture]
+ public class EndFeatureMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwnedMemberFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IEndFeatureMembership)null).ComputeOwnedMemberFeature());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/EnumerationDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/EnumerationDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..e3fa6ba7
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/EnumerationDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Enumerations;
+
+ [TestFixture]
+ public class EnumerationDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeEnumeratedValue_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IEnumerationDefinition)null).ComputeEnumeratedValue());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/EnumerationUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/EnumerationUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..660ebd66
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/EnumerationUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Enumerations;
+
+ [TestFixture]
+ public class EnumerationUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeEnumerationDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IEnumerationUsage)null).ComputeEnumerationDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/EventOccurrenceUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/EventOccurrenceUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..66283618
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/EventOccurrenceUsageExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Occurrences;
+
+ [TestFixture]
+ public class EventOccurrenceUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeEventOccurrence_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IEventOccurrenceUsage)null).ComputeEventOccurrence());
+ }
+
+ [Test]
+ public void ComputeIsReference_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IEventOccurrenceUsage)null).ComputeIsReference());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ExhibitStateUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ExhibitStateUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..b4f11a09
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ExhibitStateUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.States;
+
+ [TestFixture]
+ public class ExhibitStateUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeExhibitedState_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IExhibitStateUsage)null).ComputeExhibitedState());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ExpressionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ExpressionExtensionsTestFixture.cs
new file mode 100644
index 00000000..6449ab53
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ExpressionExtensionsTestFixture.cs
@@ -0,0 +1,50 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Functions;
+
+ [TestFixture]
+ public class ExpressionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeFunction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IExpression)null).ComputeFunction());
+ }
+
+ [Test]
+ public void ComputeIsModelLevelEvaluable_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IExpression)null).ComputeIsModelLevelEvaluable());
+ }
+
+ [Test]
+ public void ComputeResult_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IExpression)null).ComputeResult());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/FeatureChainExpressionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/FeatureChainExpressionExtensionsTestFixture.cs
new file mode 100644
index 00000000..9d1be1d3
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/FeatureChainExpressionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Expressions;
+
+ [TestFixture]
+ public class FeatureChainExpressionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeTargetFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeatureChainExpression)null).ComputeTargetFeature());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/FeatureChainingExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/FeatureChainingExtensionsTestFixture.cs
new file mode 100644
index 00000000..fa55eaa5
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/FeatureChainingExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Features;
+
+ [TestFixture]
+ public class FeatureChainingExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeFeatureChained_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeatureChaining)null).ComputeFeatureChained());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/FeatureExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/FeatureExtensionsTestFixture.cs
new file mode 100644
index 00000000..5a01ca53
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/FeatureExtensionsTestFixture.cs
@@ -0,0 +1,128 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Features;
+
+ [TestFixture]
+ public class FeatureExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeChainingFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeChainingFeature());
+ }
+
+ [Test]
+ public void ComputeCrossFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeCrossFeature());
+ }
+
+ [Test]
+ public void ComputeEndOwningType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeEndOwningType());
+ }
+
+ [Test]
+ public void ComputeFeatureTarget_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeFeatureTarget());
+ }
+
+ [Test]
+ public void ComputeFeaturingType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeFeaturingType());
+ }
+
+ [Test]
+ public void ComputeOwnedCrossSubsetting_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeOwnedCrossSubsetting());
+ }
+
+ [Test]
+ public void ComputeOwnedFeatureChaining_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeOwnedFeatureChaining());
+ }
+
+ [Test]
+ public void ComputeOwnedFeatureInverting_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeOwnedFeatureInverting());
+ }
+
+ [Test]
+ public void ComputeOwnedRedefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeOwnedRedefinition());
+ }
+
+ [Test]
+ public void ComputeOwnedReferenceSubsetting_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeOwnedReferenceSubsetting());
+ }
+
+ [Test]
+ public void ComputeOwnedSubsetting_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeOwnedSubsetting());
+ }
+
+ [Test]
+ public void ComputeOwnedTypeFeaturing_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeOwnedTypeFeaturing());
+ }
+
+ [Test]
+ public void ComputeOwnedTyping_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeOwnedTyping());
+ }
+
+ [Test]
+ public void ComputeOwningFeatureMembership_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeOwningFeatureMembership());
+ }
+
+ [Test]
+ public void ComputeOwningType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeOwningType());
+ }
+
+ [Test]
+ public void ComputeType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeature)null).ComputeType());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/FeatureInvertingExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/FeatureInvertingExtensionsTestFixture.cs
new file mode 100644
index 00000000..575607e8
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/FeatureInvertingExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Features;
+
+ [TestFixture]
+ public class FeatureInvertingExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwningFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeatureInverting)null).ComputeOwningFeature());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/FeatureMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/FeatureMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..57e8c6dc
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/FeatureMembershipExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Types;
+
+ [TestFixture]
+ public class FeatureMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwnedMemberFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeatureMembership)null).ComputeOwnedMemberFeature());
+ }
+
+ [Test]
+ public void ComputeOwningType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeatureMembership)null).ComputeOwningType());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/FeatureReferenceExpressionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/FeatureReferenceExpressionExtensionsTestFixture.cs
new file mode 100644
index 00000000..3e57f3ba
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/FeatureReferenceExpressionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Expressions;
+
+ [TestFixture]
+ public class FeatureReferenceExpressionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeReferent_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeatureReferenceExpression)null).ComputeReferent());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/FeatureTypingExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/FeatureTypingExtensionsTestFixture.cs
new file mode 100644
index 00000000..edc2a70d
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/FeatureTypingExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Features;
+
+ [TestFixture]
+ public class FeatureTypingExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwningFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeatureTyping)null).ComputeOwningFeature());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/FeatureValueExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/FeatureValueExtensionsTestFixture.cs
new file mode 100644
index 00000000..3400acc5
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/FeatureValueExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.FeatureValues;
+
+ [TestFixture]
+ public class FeatureValueExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeFeatureWithValue_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeatureValue)null).ComputeFeatureWithValue());
+ }
+
+ [Test]
+ public void ComputeValue_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFeatureValue)null).ComputeValue());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/FlowDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/FlowDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..d071df89
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/FlowDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Flows;
+
+ [TestFixture]
+ public class FlowDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeFlowEnd_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFlowDefinition)null).ComputeFlowEnd());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/FlowExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/FlowExtensionsTestFixture.cs
new file mode 100644
index 00000000..d966dac8
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/FlowExtensionsTestFixture.cs
@@ -0,0 +1,68 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Interactions;
+
+ [TestFixture]
+ public class FlowExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeFlowEnd_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFlow)null).ComputeFlowEnd());
+ }
+
+ [Test]
+ public void ComputeInteraction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFlow)null).ComputeInteraction());
+ }
+
+ [Test]
+ public void ComputePayloadFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFlow)null).ComputePayloadFeature());
+ }
+
+ [Test]
+ public void ComputePayloadType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFlow)null).ComputePayloadType());
+ }
+
+ [Test]
+ public void ComputeSourceOutputFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFlow)null).ComputeSourceOutputFeature());
+ }
+
+ [Test]
+ public void ComputeTargetInputFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFlow)null).ComputeTargetInputFeature());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/FlowUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/FlowUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..c872e295
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/FlowUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Flows;
+
+ [TestFixture]
+ public class FlowUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeFlowDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFlowUsage)null).ComputeFlowDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ForLoopActionUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ForLoopActionUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..80e8f523
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ForLoopActionUsageExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Actions;
+
+ [TestFixture]
+ public class ForLoopActionUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeLoopVariable_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IForLoopActionUsage)null).ComputeLoopVariable());
+ }
+
+ [Test]
+ public void ComputeSeqArgument_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IForLoopActionUsage)null).ComputeSeqArgument());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/FramedConcernMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/FramedConcernMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..a0ff1028
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/FramedConcernMembershipExtensionsTestFixture.cs
@@ -0,0 +1,43 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Requirements;
+
+ [TestFixture]
+ public class FramedConcernMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwnedConcern_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFramedConcernMembership)null).ComputeOwnedConcern());
+ }
+ [Test]
+ public void ComputeReferencedConcern_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFramedConcernMembership)null).ComputeReferencedConcern());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/FunctionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/FunctionExtensionsTestFixture.cs
new file mode 100644
index 00000000..ee4c1b53
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/FunctionExtensionsTestFixture.cs
@@ -0,0 +1,50 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Functions;
+
+ [TestFixture]
+ public class FunctionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeExpression_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFunction)null).ComputeExpression());
+ }
+
+ [Test]
+ public void ComputeIsModelLevelEvaluable_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFunction)null).ComputeIsModelLevelEvaluable());
+ }
+
+ [Test]
+ public void ComputeResult_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IFunction)null).ComputeResult());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/IfActionUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/IfActionUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..f6cc3122
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/IfActionUsageExtensionsTestFixture.cs
@@ -0,0 +1,50 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Actions;
+
+ [TestFixture]
+ public class IfActionUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeElseAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IIfActionUsage)null).ComputeElseAction());
+ }
+
+ [Test]
+ public void ComputeIfArgument_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IIfActionUsage)null).ComputeIfArgument());
+ }
+
+ [Test]
+ public void ComputeThenAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IIfActionUsage)null).ComputeThenAction());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ImportExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ImportExtensionsTestFixture.cs
new file mode 100644
index 00000000..da9adf40
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ImportExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Root.Namespaces;
+
+ [TestFixture]
+ public class ImportExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeImportedElement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IImport)null).ComputeImportedElement());
+ }
+
+ [Test]
+ public void ComputeImportOwningNamespace_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IImport)null).ComputeImportOwningNamespace());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/IncludeUseCaseUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/IncludeUseCaseUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..bc20f8a6
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/IncludeUseCaseUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.UseCases;
+
+ [TestFixture]
+ public class IncludeUseCaseUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeUseCaseIncluded_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IIncludeUseCaseUsage)null).ComputeUseCaseIncluded());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/InstantiationExpressionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/InstantiationExpressionExtensionsTestFixture.cs
new file mode 100644
index 00000000..7a90e379
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/InstantiationExpressionExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Expressions;
+
+ [TestFixture]
+ public class InstantiationExpressionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeArgument_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IInstantiationExpression)null).ComputeArgument());
+ }
+
+ [Test]
+ public void ComputeInstantiatedType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IInstantiationExpression)null).ComputeInstantiatedType());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/InterfaceDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/InterfaceDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..15c08524
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/InterfaceDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Interfaces;
+
+ [TestFixture]
+ public class InterfaceDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeInterfaceEnd_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IInterfaceDefinition)null).ComputeInterfaceEnd());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/InterfaceUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/InterfaceUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..4d85e752
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/InterfaceUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Interfaces;
+
+ [TestFixture]
+ public class InterfaceUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeInterfaceDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IInterfaceUsage)null).ComputeInterfaceDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/IntersectingExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/IntersectingExtensionsTestFixture.cs
new file mode 100644
index 00000000..d8c3a1c6
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/IntersectingExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Types;
+
+ [TestFixture]
+ public class IntersectingExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeTypeIntersected_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IIntersecting)null).ComputeTypeIntersected());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ItemUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ItemUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..f03e1709
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ItemUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Items;
+
+ [TestFixture]
+ public class ItemUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeItemDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IItemUsage)null).ComputeItemDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/LoopActionUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/LoopActionUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..f1dadcb2
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/LoopActionUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Actions;
+
+ [TestFixture]
+ public class LoopActionUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeBodyAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ILoopActionUsage)null).ComputeBodyAction());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/MembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/MembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..73c3f25f
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/MembershipExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Root.Namespaces;
+
+ [TestFixture]
+ public class MembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeMemberElementId_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IMembership)null).ComputeMemberElementId());
+ }
+
+ [Test]
+ public void ComputeMembershipOwningNamespace_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IMembership)null).ComputeMembershipOwningNamespace());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/MetadataAccessExpressionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/MetadataAccessExpressionExtensionsTestFixture.cs
new file mode 100644
index 00000000..afe33a21
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/MetadataAccessExpressionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Expressions;
+
+ [TestFixture]
+ public class MetadataAccessExpressionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeReferencedElement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IMetadataAccessExpression)null).ComputeReferencedElement());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/MetadataFeatureExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/MetadataFeatureExtensionsTestFixture.cs
new file mode 100644
index 00000000..92c251f7
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/MetadataFeatureExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Metadata;
+
+ [TestFixture]
+ public class MetadataFeatureExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeMetaclass_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IMetadataFeature)null).ComputeMetaclass());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/MetadataUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/MetadataUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..8a754741
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/MetadataUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Metadata;
+
+ [TestFixture]
+ public class MetadataUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeMetadataDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IMetadataUsage)null).ComputeMetadataDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/MultiplicityRangeExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/MultiplicityRangeExtensionsTestFixture.cs
new file mode 100644
index 00000000..fc6747b4
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/MultiplicityRangeExtensionsTestFixture.cs
@@ -0,0 +1,50 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Multiplicities;
+
+ [TestFixture]
+ public class MultiplicityRangeExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeBound_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IMultiplicityRange)null).ComputeBound());
+ }
+
+ [Test]
+ public void ComputeLowerBound_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IMultiplicityRange)null).ComputeLowerBound());
+ }
+
+ [Test]
+ public void ComputeUpperBound_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IMultiplicityRange)null).ComputeUpperBound());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ObjectiveMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ObjectiveMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..61c91375
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ObjectiveMembershipExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Cases;
+
+ [TestFixture]
+ public class ObjectiveMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwnedObjectiveRequirement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IObjectiveMembership)null).ComputeOwnedObjectiveRequirement());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/OccurrenceUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/OccurrenceUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..38218a38
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/OccurrenceUsageExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Occurrences;
+
+ [TestFixture]
+ public class OccurrenceUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeIndividualDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IOccurrenceUsage)null).ComputeIndividualDefinition());
+ }
+
+ [Test]
+ public void ComputeOccurrenceDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IOccurrenceUsage)null).ComputeOccurrenceDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/OwningMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/OwningMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..a8f71a80
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/OwningMembershipExtensionsTestFixture.cs
@@ -0,0 +1,56 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Root.Namespaces;
+
+ [TestFixture]
+ public class OwningMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwnedMemberElement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IOwningMembership)null).ComputeOwnedMemberElement());
+ }
+
+ [Test]
+ public void ComputeOwnedMemberElementId_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IOwningMembership)null).ComputeOwnedMemberElementId());
+ }
+
+ [Test]
+ public void ComputeOwnedMemberName_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IOwningMembership)null).ComputeOwnedMemberName());
+ }
+
+ [Test]
+ public void ComputeOwnedMemberShortName_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IOwningMembership)null).ComputeOwnedMemberShortName());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/PackageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/PackageExtensionsTestFixture.cs
new file mode 100644
index 00000000..9aa5101b
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/PackageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Packages;
+
+ [TestFixture]
+ public class PackageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeFilterCondition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IPackage)null).ComputeFilterCondition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ParameterMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ParameterMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..a852d8d2
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ParameterMembershipExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Behaviors;
+
+ [TestFixture]
+ public class ParameterMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwnedMemberParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IParameterMembership)null).ComputeOwnedMemberParameter());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/PartUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/PartUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..69d3be3a
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/PartUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Parts;
+
+ [TestFixture]
+ public class PartUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputePartDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IPartUsage)null).ComputePartDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/PerformActionUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/PerformActionUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..311b93bf
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/PerformActionUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Actions;
+
+ [TestFixture]
+ public class PerformActionUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputePerformedAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IPerformActionUsage)null).ComputePerformedAction());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/PortConjugationExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/PortConjugationExtensionsTestFixture.cs
new file mode 100644
index 00000000..227aa5d6
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/PortConjugationExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Ports;
+
+ [TestFixture]
+ public class PortConjugationExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeConjugatedPortDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IPortConjugation)null).ComputeConjugatedPortDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/PortDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/PortDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..628f22b5
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/PortDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Ports;
+
+ [TestFixture]
+ public class PortDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeConjugatedPortDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IPortDefinition)null).ComputeConjugatedPortDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/PortUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/PortUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..66102cf3
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/PortUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Ports;
+
+ [TestFixture]
+ public class PortUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputePortDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IPortUsage)null).ComputePortDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ReferenceSubsettingExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ReferenceSubsettingExtensionsTestFixture.cs
new file mode 100644
index 00000000..aaffc617
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ReferenceSubsettingExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Features;
+
+ [TestFixture]
+ public class ReferenceSubsettingExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeReferencingFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IReferenceSubsetting)null).ComputeReferencingFeature());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ReferenceUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ReferenceUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..b4078ad5
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ReferenceUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.DefinitionAndUsage;
+
+ [TestFixture]
+ public class ReferenceUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeIsReference_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IReferenceUsage)null).ComputeIsReference());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/RelationshipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/RelationshipExtensionsTestFixture.cs
new file mode 100644
index 00000000..2887f468
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/RelationshipExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Root.Elements;
+
+ [TestFixture]
+ public class RelationshipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeRelatedElement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRelationship)null).ComputeRelatedElement());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/RenderingDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/RenderingDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..6684c890
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/RenderingDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Views;
+
+ [TestFixture]
+ public class RenderingDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeRendering_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRenderingDefinition)null).ComputeRendering());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/RenderingUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/RenderingUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..4fb398ca
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/RenderingUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Views;
+
+ [TestFixture]
+ public class RenderingUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeRenderingDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRenderingUsage)null).ComputeRenderingDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/RequirementConstraintMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/RequirementConstraintMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..9b43ab3f
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/RequirementConstraintMembershipExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Requirements;
+
+ [TestFixture]
+ public class RequirementConstraintMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwnedConstraint_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementConstraintMembership)null).ComputeOwnedConstraint());
+ }
+
+ [Test]
+ public void ComputeReferencedConstraint_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementConstraintMembership)null).ComputeReferencedConstraint());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/RequirementDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/RequirementDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..90f1066b
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/RequirementDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,73 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Requirements;
+
+ [TestFixture]
+ public class RequirementDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeActorParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementDefinition)null).ComputeActorParameter());
+ }
+
+ [Test]
+ public void ComputeAssumedConstraint_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementDefinition)null).ComputeAssumedConstraint());
+ }
+
+ [Test]
+ public void ComputeFramedConcern_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementDefinition)null).ComputeFramedConcern());
+ }
+ [Test]
+ public void ComputeRequiredConstraint_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementDefinition)null).ComputeRequiredConstraint());
+ }
+
+ [Test]
+ public void ComputeStakeholderParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementDefinition)null).ComputeStakeholderParameter());
+ }
+
+ [Test]
+ public void ComputeSubjectParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementDefinition)null).ComputeSubjectParameter());
+ }
+
+ [Test]
+ public void ComputeText_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementDefinition)null).ComputeText());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/RequirementUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/RequirementUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..6495c4c1
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/RequirementUsageExtensionsTestFixture.cs
@@ -0,0 +1,80 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Requirements;
+
+ [TestFixture]
+ public class RequirementUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeActorParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementUsage)null).ComputeActorParameter());
+ }
+
+ [Test]
+ public void ComputeAssumedConstraint_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementUsage)null).ComputeAssumedConstraint());
+ }
+
+ [Test]
+ public void ComputeFramedConcern_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementUsage)null).ComputeFramedConcern());
+ }
+
+ [Test]
+ public void ComputeRequiredConstraint_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementUsage)null).ComputeRequiredConstraint());
+ }
+
+ [Test]
+ public void ComputeRequirementDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementUsage)null).ComputeRequirementDefinition());
+ }
+
+ [Test]
+ public void ComputeStakeholderParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementUsage)null).ComputeStakeholderParameter());
+ }
+
+ [Test]
+ public void ComputeSubjectParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementUsage)null).ComputeSubjectParameter());
+ }
+
+ [Test]
+ public void ComputeText_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementUsage)null).ComputeText());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/RequirementVerificationMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/RequirementVerificationMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..7a0d53b3
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/RequirementVerificationMembershipExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.VerificationCases;
+
+ [TestFixture]
+ public class RequirementVerificationMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwnedRequirement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementVerificationMembership)null).ComputeOwnedRequirement());
+ }
+
+ [Test]
+ public void ComputeVerifiedRequirement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IRequirementVerificationMembership)null).ComputeVerifiedRequirement());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/ResultExpressionMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/ResultExpressionMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..17c96cf9
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/ResultExpressionMembershipExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Functions;
+
+ [TestFixture]
+ public class ResultExpressionMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwnedResultExpression_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IResultExpressionMembership)null).ComputeOwnedResultExpression());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/SatisfyRequirementUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/SatisfyRequirementUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..7bbd2f55
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/SatisfyRequirementUsageExtensionsTestFixture.cs
@@ -0,0 +1,43 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Requirements;
+
+ [TestFixture]
+ public class SatisfyRequirementUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeSatisfiedRequirement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ISatisfyRequirementUsage)null).ComputeSatisfiedRequirement());
+ }
+ [Test]
+ public void ComputeSatisfyingFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ISatisfyRequirementUsage)null).ComputeSatisfyingFeature());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/SendActionUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/SendActionUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..e827c974
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/SendActionUsageExtensionsTestFixture.cs
@@ -0,0 +1,50 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Actions;
+
+ [TestFixture]
+ public class SendActionUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputePayloadArgument_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ISendActionUsage)null).ComputePayloadArgument());
+ }
+
+ [Test]
+ public void ComputeReceiverArgument_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ISendActionUsage)null).ComputeReceiverArgument());
+ }
+
+ [Test]
+ public void ComputeSenderArgument_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ISendActionUsage)null).ComputeSenderArgument());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/SpecializationExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/SpecializationExtensionsTestFixture.cs
new file mode 100644
index 00000000..ca1cf51a
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/SpecializationExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Types;
+
+ [TestFixture]
+ public class SpecializationExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwningType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ISpecialization)null).ComputeOwningType());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/StakeholderMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/StakeholderMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..90b0b52c
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/StakeholderMembershipExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Requirements;
+
+ [TestFixture]
+ public class StakeholderMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwnedStakeholderParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IStakeholderMembership)null).ComputeOwnedStakeholderParameter());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/StateDefinitionExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/StateDefinitionExtensionsTestFixture.cs
new file mode 100644
index 00000000..b51404bd
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/StateDefinitionExtensionsTestFixture.cs
@@ -0,0 +1,56 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.States;
+
+ [TestFixture]
+ public class StateDefinitionExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeDoAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IStateDefinition)null).ComputeDoAction());
+ }
+
+ [Test]
+ public void ComputeEntryAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IStateDefinition)null).ComputeEntryAction());
+ }
+
+ [Test]
+ public void ComputeExitAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IStateDefinition)null).ComputeExitAction());
+ }
+
+ [Test]
+ public void ComputeState_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IStateDefinition)null).ComputeState());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/StateSubactionMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/StateSubactionMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..5492cc4e
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/StateSubactionMembershipExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.States;
+
+ [TestFixture]
+ public class StateSubactionMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IStateSubactionMembership)null).ComputeAction());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/StateUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/StateUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..fed4d4a2
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/StateUsageExtensionsTestFixture.cs
@@ -0,0 +1,56 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.States;
+
+ [TestFixture]
+ public class StateUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeDoAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IStateUsage)null).ComputeDoAction());
+ }
+
+ [Test]
+ public void ComputeEntryAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IStateUsage)null).ComputeEntryAction());
+ }
+
+ [Test]
+ public void ComputeExitAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IStateUsage)null).ComputeExitAction());
+ }
+
+ [Test]
+ public void ComputeStateDefinition_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IStateUsage)null).ComputeStateDefinition());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/StepExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/StepExtensionsTestFixture.cs
new file mode 100644
index 00000000..61767af8
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/StepExtensionsTestFixture.cs
@@ -0,0 +1,44 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Kernel.Behaviors;
+
+ [TestFixture]
+ public class StepExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeBehavior_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IStep)null).ComputeBehavior());
+ }
+
+ [Test]
+ public void ComputeParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IStep)null).ComputeParameter());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/SubclassificationExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/SubclassificationExtensionsTestFixture.cs
new file mode 100644
index 00000000..f9099620
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/SubclassificationExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Classifiers;
+
+ [TestFixture]
+ public class SubclassificationExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwningClassifier_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ISubclassification)null).ComputeOwningClassifier());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/SubjectMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/SubjectMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..6d938d0a
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/SubjectMembershipExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Requirements;
+
+ [TestFixture]
+ public class SubjectMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwnedSubjectParameter_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ISubjectMembership)null).ComputeOwnedSubjectParameter());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/SubsettingExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/SubsettingExtensionsTestFixture.cs
new file mode 100644
index 00000000..747b3573
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/SubsettingExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Features;
+
+ [TestFixture]
+ public class SubsettingExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeOwningFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ISubsetting)null).ComputeOwningFeature());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/TerminateActionUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/TerminateActionUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..b46eefc5
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/TerminateActionUsageExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.Actions;
+
+ [TestFixture]
+ public class TerminateActionUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeTerminatedOccurrenceArgument_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ITerminateActionUsage)null).ComputeTerminatedOccurrenceArgument());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/TextualRepresentationExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/TextualRepresentationExtensionsTestFixture.cs
new file mode 100644
index 00000000..d13b4c1c
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/TextualRepresentationExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Root.Annotations;
+
+ [TestFixture]
+ public class TextualRepresentationExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeRepresentedElement_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ITextualRepresentation)null).ComputeRepresentedElement());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/TransitionFeatureMembershipExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/TransitionFeatureMembershipExtensionsTestFixture.cs
new file mode 100644
index 00000000..3fd823bb
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/TransitionFeatureMembershipExtensionsTestFixture.cs
@@ -0,0 +1,38 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.States;
+
+ [TestFixture]
+ public class TransitionFeatureMembershipExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeTransitionFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ITransitionFeatureMembership)null).ComputeTransitionFeature());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/TransitionUsageExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/TransitionUsageExtensionsTestFixture.cs
new file mode 100644
index 00000000..8741e55f
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/TransitionUsageExtensionsTestFixture.cs
@@ -0,0 +1,68 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Systems.States;
+
+ [TestFixture]
+ public class TransitionUsageExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeEffectAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ITransitionUsage)null).ComputeEffectAction());
+ }
+
+ [Test]
+ public void ComputeGuardExpression_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ITransitionUsage)null).ComputeGuardExpression());
+ }
+
+ [Test]
+ public void ComputeSource_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ITransitionUsage)null).ComputeSource());
+ }
+
+ [Test]
+ public void ComputeSuccession_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ITransitionUsage)null).ComputeSuccession());
+ }
+
+ [Test]
+ public void ComputeTarget_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ITransitionUsage)null).ComputeTarget());
+ }
+
+ [Test]
+ public void ComputeTriggerAction_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((ITransitionUsage)null).ComputeTriggerAction());
+ }
+ }
+}
diff --git a/SysML2.NET.Tests/Extend/TypeExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/TypeExtensionsTestFixture.cs
new file mode 100644
index 00000000..cf261e4f
--- /dev/null
+++ b/SysML2.NET.Tests/Extend/TypeExtensionsTestFixture.cs
@@ -0,0 +1,164 @@
+// -------------------------------------------------------------------------------------------------
+//
+//
+// Copyright 2022-2026 Starion Group S.A.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// ------------------------------------------------------------------------------------------------
+
+namespace SysML2.NET.Tests.Extend
+{
+ using System;
+
+ using NUnit.Framework;
+
+ using SysML2.NET.Core.POCO.Core.Types;
+
+ [TestFixture]
+ public class TypeExtensionsTestFixture
+ {
+ [Test]
+ public void ComputeDifferencingType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IType)null).ComputeDifferencingType());
+ }
+
+ [Test]
+ public void ComputeDirectedFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IType)null).ComputeDirectedFeature());
+ }
+
+ [Test]
+ public void ComputeEndFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IType)null).ComputeEndFeature());
+ }
+
+ [Test]
+ public void ComputeFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IType)null).ComputeFeature());
+ }
+
+ [Test]
+ public void ComputeFeatureMembership_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IType)null).ComputeFeatureMembership());
+ }
+
+ [Test]
+ public void ComputeInheritedFeature_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IType)null).ComputeInheritedFeature());
+ }
+
+ [Test]
+ public void ComputeInheritedMembership_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IType)null).ComputeInheritedMembership());
+ }
+
+ [Test]
+ public void ComputeInput_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IType)null).ComputeInput());
+ }
+
+ [Test]
+ public void ComputeIntersectingType_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IType)null).ComputeIntersectingType());
+ }
+
+ [Test]
+ public void ComputeIsConjugated_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IType)null).ComputeIsConjugated());
+ }
+
+ [Test]
+ public void ComputeMultiplicity_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IType)null).ComputeMultiplicity());
+ }
+
+ [Test]
+ public void ComputeOutput_ThrowsNotSupportedException()
+ {
+ Assert.Throws(() => ((IType)null).ComputeOutput());
+ }
+
+ [Test]
+ public void ComputeOwnedConjugator_ThrowsNotSupportedException()
+ {
+ Assert.Throws