### Question:
ClusterMonitor implements Module, ClusterEventListener { @Override public void joinedCluster() { ClusterManager.getNodesInfo().forEach(nodeName -> nodeNames.put(nodeName.getNodeID(), nodeName.getHostName())); LOGGER.info("This node ({}/{}) has joined the cluster [seniorMember={}]", xmppServer.getNodeID(), xmppServer.getServerInfo().getHostname(), getSeniorMember()); } @SuppressWarnings("WeakerAccess")  ClusterMonitor(); @Override String getName(); @Override void initialize(final XMPPServer xmppServer); @Override void start(); @Override void stop(); @Override void destroy(); @Override void joinedCluster(); @Override void joinedCluster(final byte[] nodeIdBytes); @Override void leftCluster(); @Override void leftCluster(final byte[] nodeIdBytes); @Override void markedAsSeniorClusterMember();  }### Answer:
@Test public void whenAnotherNodeJoinsTheClusterNothingWillBeSent() { clusterMonitor.joinedCluster(OTHER_NODE_ID); verify(xmppServer, never()).sendMessageToAdmins(any()); }