@Override
    public InstancePort instancePort(MacAddress macAddress) {
        checkNotNull(macAddress, ERR_NULL_MAC_ADDRESS);

        return instancePortStore.instancePorts().stream()
                .filter(port -> port.macAddress().equals(macAddress))
                .findFirst().orElse(null);
    }
@Test
    public void testGetInstancePortByMac() {
        createBasicInstancePorts();
        InstancePort port = target.instancePort(MAC_ADDRESS_1);
        assertEquals("Instance port did not match", port, instancePort1);
    }