anchor.diff:      return (enclosingElement as ElementImpl).typeParameterContext;
     }
   
  -  /**
  -   * Set whether this accessor is a getter.
  -   */
  +  /// Set whether this accessor is a getter.
     void set getter(bool isGetter) {
       _assertNotResynthesized(serializedExecutable);
       setModifier(Modifier.GETTER, isGetter);
  
positive.code:   @override
    int get nameOffset => _nameOffset;
  
    /**
     * Sets the offset of the name of this element in the file that contains the
     * declaration of this element.
     */
    void set nameOffset(int offset) {
      _nameOffset = offset;
    }
  
negative.code:     return _mixins ?? const <ClassElement>[];
    }
  
    /// Set the mixins contained in this compilation unit to the given [mixins].
    void set mixins(List<ClassElement> mixins) {
      _assertNotResynthesized(_unlinkedUnit);
      for (MixinElementImpl type in mixins) {
  