public void SendMessage(IChatUi chatClient, string recipient, string messageText)
 {
     try
     {
         var message = new Message(chatClient.Username, recipient, messageText);
         Configuration.AppendToFile(recipient, message.ToString());
         chatClient.AddChatLine(message);
     }
     catch (ArgumentException ae)
     {
         chatClient.AddChatErrorLine($"Message could not be sent :: {ae.Message}");
     }
 }
        public void AddChatErrorLine(string username, string errorMessage)
        {
            IChatUi chatClient = getChatClient(username);

            chatClient.AddChatErrorLine(errorMessage);
        }