public InstanceType instanceType() {
        return instanceType;
    }
@Test
    public void checkConstruction() {
        assertThat(event1.type(), is(ClusterEvent.Type.INSTANCE_ADDED));
        assertThat(event1.subject(), is(cNode1));
        assertThat(event1.instanceType(), is(ClusterEvent.InstanceType.UNKNOWN));

        assertThat(event7.time(), is(time));
        assertThat(event7.type(), is(ClusterEvent.Type.INSTANCE_READY));
        assertThat(event7.subject(), is(cNode2));
        assertThat(event7.instanceType(), is(ClusterEvent.InstanceType.UNKNOWN));

        assertThat(event8.type(), is(ClusterEvent.Type.INSTANCE_ADDED));
        assertThat(event8.subject(), is(cNode2));
        assertThat(event8.instanceType(), is(ClusterEvent.InstanceType.ONOS));

        assertThat(event9.type(), is(ClusterEvent.Type.INSTANCE_ADDED));
        assertThat(event9.subject(), is(cNode2));
        assertThat(event9.instanceType(), is(ClusterEvent.InstanceType.STORAGE));

        assertThat(event10.type(), is(ClusterEvent.Type.INSTANCE_REMOVED));
        assertThat(event10.subject(), is(cNode2));
        assertThat(event10.instanceType(), is(ClusterEvent.InstanceType.ONOS));

        assertThat(event11.type(), is(ClusterEvent.Type.INSTANCE_REMOVED));
        assertThat(event11.subject(), is(cNode2));
        assertThat(event11.instanceType(), is(ClusterEvent.InstanceType.STORAGE));

        assertThat(event12.type(), is(ClusterEvent.Type.INSTANCE_ACTIVATED));
        assertThat(event12.subject(), is(cNode1));
        assertThat(event12.instanceType(), is(ClusterEvent.InstanceType.ONOS));

        assertThat(event13.type(), is(ClusterEvent.Type.INSTANCE_ACTIVATED));
        assertThat(event13.subject(), is(cNode1));
        assertThat(event13.instanceType(), is(ClusterEvent.InstanceType.STORAGE));

        assertThat(event14.type(), is(ClusterEvent.Type.INSTANCE_READY));
        assertThat(event14.subject(), is(cNode1));
        assertThat(event14.instanceType(), is(ClusterEvent.InstanceType.ONOS));

        assertThat(event15.type(), is(ClusterEvent.Type.INSTANCE_READY));
        assertThat(event15.subject(), is(cNode1));
        assertThat(event15.instanceType(), is(ClusterEvent.InstanceType.STORAGE));

        assertThat(event16.type(), is(ClusterEvent.Type.INSTANCE_DEACTIVATED));
        assertThat(event16.subject(), is(cNode1));
        assertThat(event16.instanceType(), is(ClusterEvent.InstanceType.ONOS));

        assertThat(event17.type(), is(ClusterEvent.Type.INSTANCE_DEACTIVATED));
        assertThat(event17.subject(), is(cNode1));
        assertThat(event17.instanceType(), is(ClusterEvent.InstanceType.STORAGE));
    }