code: function createInvalidReporterError(message, reporter) {
    var err = new TypeError(message);
    err.code = 'ERR_MOCHA_INVALID_REPORTER';
    err.reporter = reporter;
    return err;
  }
docs: Creates an error object to be thrown when the reporter specified in the options was not found.
  
  @public
  @param {string} message - Error message to be displayed.
  @param {string} reporter - User-specified reporter value.
  @returns {Error} instance detailing the error condition