code: function fail(actual, expected, message, operator, stackStartFunction) {
    var a = new Assertion(actual);
    a.params = {
      operator: operator,
      expected: expected,
      message: message,
      stackStartFunction: stackStartFunction || fail
    };
  
    a.fail();
  }
docs: 3. All of the following functions must throw an AssertionError when a corresponding condition is not met, with a message that may be undefined if not provided.  All assertion methods provide both the actual and expected values to the assertion error for display purposes. 
  Node.js standard [`assert.fail`](http://nodejs.org/api/assert.html#assert_assert_fail_actual_expected_message_operator).
  @static
  @memberOf should
  @category assertion assert
  @param {*} actual Actual object
  @param {*} expected Expected object
  @param {string} message Message for assertion
  @param {string} operator Operator text