pipeline.addLast("http-codec", new HttpClientCodec());
pipeline.addLast("aggregator", new HttpObjectAggregator(maxContentLength));
pipeline.addLast("ws-handler", handler);
pipeline.addLast("gremlin-encoder", new WebSocketGremlinRequestEncoder(true, cluster.getSerializer()));
pipeline.addLast("gremlin-decoder", new WebSocketGremlinResponseDecoder(cluster.getSerializer()));
}