Add test, make package private

Signed-off-by: Ryan Nett <JNett96@gmail.com>

Author: rnett

tensorflow-core/tensorflow-core-api/src/main/java/org/tensorflow/MRTest.java

@@ -17,8 +17,8 @@
 */
 package org.tensorflow;
 
-public class MRTest {
-  public static int version() {
+class MRTest {
+  static int version() {
     return 8;
   }
 }

tensorflow-core/tensorflow-core-api/src/main/java9/org/tensorflow/MRTest.java

@@ -17,11 +17,8 @@
  */
 package org.tensorflow;
 
-import java.lang.ref.Cleaner;
-
-public class MRTest {
-  public static int version(){
-    Cleaner.create();
+class MRTest {
+  static int version(){
     return 9;
   }
 }

tensorflow-core/tensorflow-core-api/src/test/java/org/tensorflow/MultiReleaseTest.java

@@ -0,0 +1,38 @@
+/*
+  Copyright 2021 The TensorFlow Authors. All Rights Reserved.
+
+ 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.
+ =======================================================================
+
+ */
+package org.tensorflow;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class MultiReleaseTest {
+
+  @Test
+  public void testMultirelease(){
+    String javaVersion = System.getProperty("java.version");
+    System.out.println("Testing on Java version " + javaVersion);
+    int value = MRTest.version();
+    if(javaVersion.compareTo("9") >= 0){
+      assertEquals(9, value);
+    } else {
+      assertEquals(8, value);
+    }
+  }
+
+}