C#: Re-factor the NHibernate test.

Author: michaelnebel

csharp/ql/test/library-tests/frameworks/NHibernate/DataFlow.ql

@@ -1,17 +1,15 @@
 import csharp
 
-class MyConfiguration extends TaintTracking::Configuration {
-  MyConfiguration() { this = "MyConfiguration" }
+module TaintConfig implements DataFlow::ConfigSig {
+  predicate isSource(DataFlow::Node node) { node.asExpr().(StringLiteral).getValue() = "tainted" }
 
-  override predicate isSource(DataFlow::Node node) {
-    node.asExpr().(StringLiteral).getValue() = "tainted"
-  }
-
-  override predicate isSink(DataFlow::Node node) {
+  predicate isSink(DataFlow::Node node) {
     exists(MethodCall mc | mc.getTarget().hasName("Sink") and node.asExpr() = mc.getArgument(0))
   }
 }
 
-from MyConfiguration config, DataFlow::Node source, DataFlow::Node sink
-where config.hasFlow(source, sink)
+module Taint = TaintTracking::Global<TaintConfig>;
+
+from DataFlow::Node source, DataFlow::Node sink
+where Taint::flow(source, sink)
 select sink, "Data flow from $@.", source, source.toString()