public string RunCommand(string cmd)
        {
            string fsCommand = cmd.Split(' ')[0];

            string[] args = cmd.Split(' ').Skip(1).ToArray();
            try
            {
                IFileServiceCommand fsCommandObj = FileServiceCommands.NewCommand(fsCommand.ToLower());
                string answer = fsCommandObj.Run(OperationContext.Current.SessionId, args);
                OperationContext.Current.GetCallbackChannel <IFileServiceCallback>().Notify(FileServiceSession.GetUser(OperationContext.Current.SessionId) + " " + fsCommandObj.Notify(args));
                return(answer);
            }
            catch (FileServiceCommandExeption e)
            {
                return($"Error: {e.Message}");
            }
            finally
            {
                if (Monitor.IsEntered(VirtualFileSystem.Lock))
                {
                    Monitor.Exit(VirtualFileSystem.Lock);
                }
            }
        }