showHelpAfterError(displayHelp = true) {
    if (typeof displayHelp !== 'string') displayHelp = !!displayHelp;
    this._showHelpAfterError = displayHelp;
    return this;
  }
Display the help or a custom message after an error occurs.

@param {(boolean|string)} [displayHelp]
@return {Command} `this` command for chaining