@Test
public void createResponse() throws Exception {

    //CON 205 MID:321 Token:0x3131
    assertEquals(newCoapPacket(321).con(Code.C205_CONTENT).token(0x3131).build().createResponse(),
            newCoapPacket(321).ack(null).build()); //note, no token!
    //CON GET MID:321 Token:0x3131
    assertEquals(newCoapPacket(321).get().token(0x3131).build().createResponse(),
            newCoapPacket(321).ack(Code.C205_CONTENT).token(0x3131).build());
}