void portAddedHelper(DeviceEvent event) {
        log.debug("Instance port {} is detected from {}",
                event.port().annotations().value(PORT_NAME),
                event.subject().id());
        // we check the existence of openstack port, in case VM creation
        // event comes before port creation
        if (osNetworkService.port(event.port()) != null) {
            processPortAdded(event.port());
        }
    }
@Test
    public void testProcessPortAddedForNewAddition() {
        org.onosproject.net.Port port = new DefaultPort(DEV2, P1, true, ANNOTATIONS);
        DeviceEvent event = new DeviceEvent(DeviceEvent.Type.PORT_ADDED, DEV2, port);

        target.portAddedHelper(event);

        HostId hostId = HostId.hostId(HOST_MAC2);
        HostDescription hostDesc = new DefaultHostDescription(
                HOST_MAC2,
                VlanId.NONE,
                new HostLocation(CP21, System.currentTimeMillis()),
                ImmutableSet.of(HOST_IP11),
                ANNOTATIONS

        );

        verifyHostResult(hostId, hostDesc);
    }