code: function createInvalidArgumentTypeError(message, argument, expected) {
    var err = new TypeError(message);
    err.code = 'ERR_MOCHA_INVALID_ARG_TYPE';
    err.argument = argument;
    err.expected = expected;
    err.actual = typeof argument;
    return err;
  }
docs: Creates an error object to be thrown when an argument did not use the supported type
  
  @public
  @param {string} message - Error message to be displayed.
  @param {string} argument - Argument name.
  @param {string} expected - Expected argument datatype.
  @returns {Error} instance detailing the error condition