anchor.diff:        expect(instance == instance, true);
       });
   
  +    test('should return correct hashCode', () {
  +      final instance = SimpleEquatable(true);
  +      expect(
  +        instance.hashCode,
  +        instance.runtimeType.hashCode ^ instance.data.hashCode,
  +      );
  +    });
  +
       test('should return true when instances are different', () {
         final instanceA = SimpleEquatable(true);
         final instanceB = SimpleEquatable(true);
  
positive.code:       expect(instance == instance, true);
      });
  
      test('should return true when instances are different', () {
        final instanceA = SimpleEquatable(0);
        final instanceB = SimpleEquatable(0);
  
negative.code:       expect(instance == instance, true);
      });
  
      test('should return correct hashCode', () {
        final instance = SimpleEquatable(EquatableData(
          key: 'foo',
          value: 'bar',
        ));
        expect(
          instance.hashCode,
          instance.runtimeType.hashCode ^ instance.data.hashCode,
        );
      });
  
      test('should return true when instances are different', () {
        final instanceA = SimpleEquatable(EquatableData(
          key: 'foo',
  