@Test
public void testSendArpResponse() {

	Ipv4Address srcIpv4Address = Ipv4Address.getDefaultInstance("192.168.20.1");
	Ipv4Address dstIpv4Address = Ipv4Address.getDefaultInstance("192.168.10.1");
	MacAddress srcMacAddress = new MacAddress("aa:bb:cc:dd:ee:00");
	MacAddress dstMacAddress = new MacAddress("aa:bb:cc:dd:ee:ff");
	ArpMessageAddress senderAddress = new ArpMessageAddress(srcMacAddress, srcIpv4Address);
	ArpMessageAddress receiverAddress = new ArpMessageAddress(dstMacAddress, dstIpv4Address);
	InstanceIdentifier<Node> instanceId = InstanceIdentifier.builder(Nodes.class)
			.child(Node.class, new NodeKey(new NodeId("node_001"))).toInstance();
	NodeConnectorKey nodeConnectorKey = new NodeConnectorKey(new NodeConnectorId("node_001:0xfffffffc"));
	InstanceIdentifier<NodeConnector> egressNc = instanceId.child(NodeConnector.class, nodeConnectorKey);
	Future<RpcResult<Void>> futureTransmitPacketResult = mock(Future.class);
	when(packetProcessingService.transmitPacket(any(TransmitPacketInput.class)))
			.thenReturn(futureTransmitPacketResult);
	arpSender.sendArpResponse(senderAddress, receiverAddress, egressNc, null);
	verify(packetProcessingService, times(1)).transmitPacket(any(TransmitPacketInput.class));
}