anchor.diff:      if (_evictionTimer == null) {
         void _handleEviction(Timer timer) {
           Date now = new Date.now();
  +        List<String> emptyKeys = new List<String>();
           _openSockets.forEach(
               void _(String key, Queue<_SocketConnection> connections) {
                 // As returned connections are added at the head of the
  
positive.code: 
      // If there are active connections for this key get the first one
      // otherwise create a new one.
      Queue socketConnections = _openSockets[_connectionKey(host, port)];
      if (socketConnections == null || socketConnections.isEmpty()) {
        Socket socket = new Socket(host, port);
        // Until the connection is established handle connection errors
  
negative.code:      _activeSockets.forEach((_SocketConnection socketConn) {
         socketConn._socket.close();
       });
      if (_evictionTimer != null) _cancelEvictionTimer();
       _shutdown = true;
    }
  
    void _cancelEvictionTimer() {
      _evictionTimer.cancel();
      _evictionTimer = null;
    }
  
    String _connectionKey(String host, int port) {
  