anchor.diff:    NotExpect(actual) : super(actual);
   
     void toEqual(expected) => toHaveSameProps(expected);
  -  void toBePromise() => _expect(actual is Future, equals(false));
  -  void toBeNull() => _expect(actual == null, equals(false));
  +  void toBePromise() => gns.guinness.matchers.toBeFalse(actual is Future);
  +  void toBeNull() => gns.guinness.matchers.toBeFalse(actual == null);
     Function get _expect => gns.guinness.matchers.expect;
   }
   
  
positive.code: 
    void toEqual(expected) => toHaveSameProps(expected);
    void toThrowError([message = ""]) => toThrowWith(message: message);
    void toBePromise() => _expect(actual is Future, equals(true));
    void toImplement(expected) => toBeA(expected);
    void toBeNaN() => _expect(double.NAN.compareTo(actual) == 0, equals(true));
    void toHaveText(expected) => _expect(elementText(actual), expected);
    void toHaveBeenCalledWith([a = _u, b = _u, c = _u, d = _u, e = _u, f = _u]) =>
        _expect(_argsMatch(actual, a, b, c, d, e, f), true,
  
negative.code: library test_lib.test_lib;
  
  import 'dart:async';
  
  import 'package:guinness/guinness.dart' as gns;
  export 'package:guinness/guinness.dart'
  