anchor.diff:  
     final _UninstantiatedBoundChecker _uninstantiatedBoundChecker;
   
  -  /// Setting this flag to `true` disables the check for conflicting generics.
  -  /// This is used when running with the old task model to work around
  -  /// dartbug.com/32421.
  -  ///
  -  /// TODO(paulberry): remove this flag once dartbug.com/32421 is properly
  -  /// fixed.
  -  final bool disableConflictingGenericsCheck;
  -
     /// The features enabled in the unit currently being checked for errors.
     FeatureSet _featureSet;
   
  
positive.code:         implementsClause?.interfaces,
          CompileTimeErrorCode.IMPLEMENTS_REPEATED,
        );
        if (!disableConflictingGenericsCheck) {
          _checkForConflictingGenerics(node);
        }
      }
    }
  
  
negative.code:       _checkImplementsSuperClass(implementsClause);
        _checkMixinInference(node, withClause);
        _checkForMixinWithConflictingPrivateMember(withClause, superclass);
        _checkForConflictingGenerics(node);
      }
    }
  
  