public void Expect_the_ack_request_to_be_sent()
 {
     MessageSenderMock.Verify((ms) => ms.SendRequest(It.Is <SipRequest>(r => r.RequestLine.Method == SipMethods.Ack)), Times.Once());
 }
 public void Expect_the_Request_to_be_sent()
 {
     MessageSenderMock.Verify((ms) => ms.SendRequest(It.IsAny <SipRequest>()), Times.Once());
 }