public override async Task Run()
        {
            while (true)
            {
                var line = consoleHost.ReadLine("$ ").Trim();
                if (string.IsNullOrWhiteSpace(line))
                {
                    continue;
                }

                try
                {
                    if (Exit(line))
                    {
                        break;
                    }

                    await Handle(line);
                }
                catch (ParserException ex)
                {
                    consoleHost.WriteLine(ex.Message);
                }
            }
        }