Unbind the ID generator when the test is complete

This was causing intermittent failures in some intent tests
because the id generator was not unbound and subsequent
tests would fail trying to assign a new one.

Change-Id: Id10caf69c32383b27d246426c29972b7654b40bb

@@ -15,9 +15,15 @@
  */
  */
 package org.onosproject.vpls;
 package org.onosproject.vpls;
 
 
-import com.google.common.collect.Sets;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.stream.Collectors;
+
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Before;
-import org.junit.BeforeClass;
 import org.junit.Test;
 import org.junit.Test;
 import org.onlab.packet.Ip4Address;
 import org.onlab.packet.Ip4Address;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.MacAddress;
@@ -56,16 +62,14 @@ import org.onosproject.net.provider.ProviderId;
 import org.onosproject.routing.IntentSynchronizationAdminService;
 import org.onosproject.routing.IntentSynchronizationAdminService;
 import org.onosproject.routing.IntentSynchronizationService;
 import org.onosproject.routing.IntentSynchronizationService;
 
 
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.Set;
-import java.util.concurrent.atomic.AtomicLong;
-import java.util.stream.Collectors;
+import com.google.common.collect.Sets;
 
 
 import static java.lang.String.format;
 import static java.lang.String.format;
-import static org.easymock.EasyMock.*;
+import static org.easymock.EasyMock.anyObject;
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.expect;
 import static org.easymock.EasyMock.expectLastCall;
 import static org.easymock.EasyMock.expectLastCall;
+import static org.easymock.EasyMock.replay;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.assertTrue;
 
 
@@ -132,14 +136,13 @@ public class VplsTest {
 
 
     private static final ProviderId PID = new ProviderId("of", "foo");
     private static final ProviderId PID = new ProviderId("of", "foo");
 
 
-    @BeforeClass
-    public static void setUpClass() {
-        IdGenerator idGenerator = new TestIdGenerator();
-        Intent.bindIdGenerator(idGenerator);
-    }
+    private static IdGenerator idGenerator;
 
 
     @Before
     @Before
     public void setUp() throws Exception {
     public void setUp() throws Exception {
+        idGenerator = new TestIdGenerator();
+        Intent.bindIdGenerator(idGenerator);
+
         applicationService = createMock(ApplicationService.class);
         applicationService = createMock(ApplicationService.class);
 
 
         coreService = createMock(CoreService.class);
         coreService = createMock(CoreService.class);
@@ -170,6 +173,11 @@ public class VplsTest {
         vpls.intentSynchronizerAdmin = intentSynchronizer;
         vpls.intentSynchronizerAdmin = intentSynchronizer;
     }
     }
 
 
+    @After
+    public void tearDown() {
+        Intent.unbindIdGenerator(idGenerator);
+    }
+
     /**
     /**
      * Creates the interface configuration. On devices 1, 2 and 3 is configured
      * Creates the interface configuration. On devices 1, 2 and 3 is configured
      * an interface on port 1 with vlan 1. On devices 4, 5 and 6 is configured
      * an interface on port 1 with vlan 1. On devices 4, 5 and 6 is configured