Fix buck tests

Change-Id: I3d681e6e5c1d3e98c87ccb3d20a619b216ae6133
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 5e84cd8..433a201 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
@@ -23,6 +23,14 @@
  * Mock id generator for testing.
  */
 public class MockIdGenerator implements IdGenerator {
+
+    private static boolean generatorIsBound = false;
+    public static void bindNewGenerator() {
+        if (!generatorIsBound) {
+            generatorIsBound = true;
+            Intent.bindIdGenerator(new MockIdGenerator());
+        }
+    }
     private AtomicLong nextId = new AtomicLong(0);
 
     @Override