boolean isHeartbeatTopic(String topic) {
        return replicationPolicy.isHeartbeatsTopic(topic);
    }
@Test
    public void testIsHeartbeatTopic() {
        MirrorClient client = new FakeMirrorClient();
        assertTrue(client.isHeartbeatTopic("heartbeats"));
        assertTrue(client.isHeartbeatTopic("source1.heartbeats"));
        assertTrue(client.isHeartbeatTopic("source2.source1.heartbeats"));
        assertFalse(client.isHeartbeatTopic("heartbeats!"));
        assertFalse(client.isHeartbeatTopic("!heartbeats"));
        assertFalse(client.isHeartbeatTopic("source1heartbeats"));
        assertFalse(client.isHeartbeatTopic("source1-heartbeats"));
    }