anchor.diff:      return map.putIfAbsent(
           name,
           () =>
  -            hierarchy.getDispatchTarget(c, Name(name)) ??
  -            hierarchy.getDispatchTarget(c, Name(name), setter: true));
  +            _hierarchy.getDispatchTarget(c, Name(name)) ??
  +            _hierarchy.getDispatchTarget(c, Name(name), setter: true));
     }
   
     js_ast.Expression _emitStaticMemberName(String name, [NamedNode member]) {
  
positive.code: 
    /// Information about virtual fields for all libraries in the current build
    /// unit.
    final virtualFields = VirtualFieldModel();
  
    final JSTypeRep _typeRep;
  
  
negative.code: 
    js_ast.Expression _emitCast(js_ast.Expression expr, DartType type,
        {bool implicit = true}) {
      if (_types.isTop(type)) return expr;
  
      var code = implicit ? '#._check(#)' : '#.as(#)';
      return js.call(code, [_emitType(type), expr]);
  