public override void MissingOptions(MissingOptionsException ex, string passedArguments)
 {
     DisplayException(ex, passedArguments);
 }
 /// <summary>
 ///     Displays an error and exits.
 ///     Use this when a user fails to pass a required command line option.
 /// </summary>
 public abstract void MissingOptions(MissingOptionsException ex, string passedArguments);