Adding unit tests for the comm manager.

+package org.onlab.onos.store.cluster.impl;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.onos.cluster.DefaultControllerNode;
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.store.cluster.messaging.SerializationService;
+import org.onlab.packet.IpPrefix;
+import sun.jvm.hotspot.TestDebugger;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.Assert.*;
+
+/**
+ * Tests of the cluster communication manager.
+ */
+public class ClusterCommunicationManagerTest {
+
+    private static final NodeId N1 = new NodeId("n1");
+    private static final NodeId N2 = new NodeId("n2");
+
+    private static final int P1 = 9881;
+    private static final int P2 = 9882;
+
+    private static final IpPrefix IP = IpPrefix.valueOf("127.0.0.1");
+
+    private ClusterCommunicationManager ccm1;
+    private ClusterCommunicationManager ccm2;
+
+    private TestDelegate cnd1 = new TestDelegate();
+    private TestDelegate cnd2 = new TestDelegate();
+
+    private DefaultControllerNode node1 = new DefaultControllerNode(N1, IP, P1);
+    private DefaultControllerNode node2 = new DefaultControllerNode(N2, IP, P2);
+
+    @Before
+    public void setUp() {
+        MessageSerializer messageSerializer = new MessageSerializer();
+        messageSerializer.activate();
+
+        ccm1 = new ClusterCommunicationManager();
+        ccm1.serializationService = messageSerializer;
+        ccm1.activate();
+
+        ccm2 = new ClusterCommunicationManager();
+        ccm2.serializationService = messageSerializer;
+        ccm2.activate();
+
+        ccm1.startUp(node1, cnd1);
+        ccm2.startUp(node2, cnd2);
+    }
+
+    @After
+    public void tearDown() {
+        ccm1.deactivate();
+        ccm2.deactivate();
+    }
+
+    @Test
+    public void connect() throws Exception {
+        cnd1.latch = new CountDownLatch(1);
+        cnd2.latch = new CountDownLatch(1);
+
+        ccm1.addNode(node2);
+        validateDelegateEvent(cnd1, Op.DETECTED, node2.id());
+        validateDelegateEvent(cnd2, Op.DETECTED, node1.id());
+    }
+
+    @Test
+    public void disconnect() throws Exception {
+        cnd1.latch = new CountDownLatch(1);
+        cnd2.latch = new CountDownLatch(1);
+
+        ccm1.addNode(node2);
+        validateDelegateEvent(cnd1, Op.DETECTED, node2.id());
+        validateDelegateEvent(cnd2, Op.DETECTED, node1.id());
+
+        cnd1.latch = new CountDownLatch(1);
+        cnd2.latch = new CountDownLatch(1);
+        ccm1.deactivate();
+//
+//        validateDelegateEvent(cnd2, Op.VANISHED, node1.id());
+    }
+
+    private void validateDelegateEvent(TestDelegate delegate, Op op, NodeId nodeId)
+            throws InterruptedException {
+        assertTrue("did not connect in time", delegate.latch.await(2500, TimeUnit.MILLISECONDS));
+        assertEquals("incorrect event", op, delegate.op);
+        assertEquals("incorrect event node", nodeId, delegate.nodeId);
+    }
+
+    enum Op { DETECTED, VANISHED, REMOVED };
+
+    private class TestDelegate implements ClusterNodesDelegate {
+
+        Op op;
+        CountDownLatch latch;
+        NodeId nodeId;
+
+        @Override
+        public DefaultControllerNode nodeDetected(NodeId nodeId, IpPrefix ip, int tcpPort) {
+            latch(nodeId, Op.DETECTED);
+            return new DefaultControllerNode(nodeId, ip, tcpPort);
+        }
+
+        @Override
+        public void nodeVanished(NodeId nodeId) {
+            latch(nodeId, Op.VANISHED);
+        }
+
+        @Override
+        public void nodeRemoved(NodeId nodeId) {
+            latch(nodeId, Op.REMOVED);
+        }
+
+        private void latch(NodeId nodeId, Op op) {
+            this.op = op;
+            this.nodeId = nodeId;
+            latch.countDown();
+        }
+    }
+}
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