PresentationLoop.cs

 static void Main(string[] args)
{
  do
  {
      Console.Write("Enter command or 'exit' to quit: > ");
      var command = Console.ReadLine();
      if ((command ?? string.Empty).Equals("exit", StringComparison.OrdinalIgnoreCase))
      {
          Console.WriteLine("Quitting.");
          break;
      }

  } while (true);
}