Added code to intent unit tests to pre-emptively unbind ID generator to avoid cascading failures.

Change-Id: I2e5aff44a90ceeaaad71d7154b79f20edab620a7
diff --git a/core/api/src/test/java/org/onosproject/net/intent/IntentDataTest.java b/core/api/src/test/java/org/onosproject/net/intent/IntentDataTest.java
index 77b9030..de215c6 100644
--- a/core/api/src/test/java/org/onosproject/net/intent/IntentDataTest.java
+++ b/core/api/src/test/java/org/onosproject/net/intent/IntentDataTest.java
@@ -55,6 +55,7 @@
     @Before
     public void setUpTest() {
         idGenerator = new MockIdGenerator();
+        Intent.unbindIdGenerator(idGenerator);
         Intent.bindIdGenerator(idGenerator);
 
         timestamp1 = new MockTimestamp(1);
diff --git a/core/api/src/test/java/org/onosproject/net/intent/IntentServiceTest.java b/core/api/src/test/java/org/onosproject/net/intent/IntentServiceTest.java
index e4d906b..1bafca8 100644
--- a/core/api/src/test/java/org/onosproject/net/intent/IntentServiceTest.java
+++ b/core/api/src/test/java/org/onosproject/net/intent/IntentServiceTest.java
@@ -47,6 +47,7 @@
     public void setUp() {
         service = createIntentService();
         service.addListener(listener);
+        Intent.unbindIdGenerator(idGenerator);
         Intent.bindIdGenerator(idGenerator);
     }
 
diff --git a/core/api/src/test/java/org/onosproject/net/intent/MockIdGenerator.java b/core/api/src/test/java/org/onosproject/net/intent/MockIdGenerator.java
index 02e8de1..2059cfc 100644
--- a/core/api/src/test/java/org/onosproject/net/intent/MockIdGenerator.java
+++ b/core/api/src/test/java/org/onosproject/net/intent/MockIdGenerator.java
@@ -25,10 +25,13 @@
 public class MockIdGenerator implements IdGenerator {
 
     private static boolean generatorIsBound = false;
+    private static MockIdGenerator idGenerator;
     public static void bindNewGenerator() {
         if (!generatorIsBound) {
             generatorIsBound = true;
-            Intent.bindIdGenerator(new MockIdGenerator());
+            idGenerator = new MockIdGenerator();
+            Intent.unbindIdGenerator(idGenerator);
+            Intent.bindIdGenerator(idGenerator);
         }
     }
     private AtomicLong nextId = new AtomicLong(0);