anchor.diff:    }
   
     /**** Internal implementation details ****/
  -  _get_id() native "RawReceivePortImpl_get_id";
  -  _get_sendport() native "RawReceivePortImpl_get_sendport";
  +  int _get_id() native "RawReceivePortImpl_get_id";
  +  SendPort _get_sendport() native "RawReceivePortImpl_get_sendport";
   
     // Called from the VM to retrieve the handler for a message.
     @pragma("vm:entry-point", "call")
  
positive.code:     _portMap[id]!['handler'] = value;
    }
  
    static final _portMap = <dynamic, Map<String, dynamic>>{};
  }
  
  @pragma("vm:entry-point")
  
negative.code:   _setActive(bool active) native "RawReceivePortImpl_setActive";
  
    void set handler(Function? value) {
      final int id = this._get_id();
      if (!_portMap.containsKey(id)) {
        _portMap[id] = <String, dynamic>{
          'port': this,
  