private void AddCommandLineExecute()
        {
            PrimitiveViewModel <string> commandLine = string.Empty;

            commandLine.RemoveRequested += HandleCommandLineRemoveRequested;
            CommandLines.Add(commandLine);
        }
 private void AddCommandLines(params string[] lines)
 {
     foreach (string line in lines)
     {
         var commandline = new PrimitiveViewModel <string>(line);
         commandline.RemoveRequested += HandleCommandLineRemoveRequested;
         CommandLines.Add(commandline);
     }
 }