public void TestAddMessage()
        {
            mockConversationRepository.Setup(x => x.FindPrivateConversationByReceiverId(It.IsAny <string>())).Returns(conversation);
            mockConversationRepository.Setup(x => x.Update(It.IsAny <Conversation>())).Returns(conversation);
            mockMessageRepository.Setup(x => x.Add(It.IsAny <MessageDetail>())).Returns(messageDetail);
            var           chatService         = new ChatService.Services.ChatService(mockConversationRepository.Object, mockMessageRepository.Object);
            MessageDetail messageDetailActual = chatService.AddMessage("5d4d0x2613376b00013a898z", messageDetail);

            Assert.AreEqual(messageDetailActual, messageDetail);
        }