anchor.diff:    }
   
     void _heartbeat() {
  +    if (this._socket.closeCode != null) return;
       this.send("HEARTBEAT", _sequence);
     }
   
  
positive.code:   }
  
    void _handleErr() {
      switch (this._socket.closeCode) {
        case 1005:
          return;
  
negative.code:   /// Whether or not the shard is ready.
    bool ready;
  
    Timer _heartbeatTimer;
    _WS _ws;
    w_transport.WebSocket _socket;
    int _sequence;
  