private DatagramChannel newChannel(
ChannelFactory<? extends DatagramChannel> channelFactory, InetSocketAddress localAddress) {
Bootstrap b = new Bootstrap();
b.group(executor());
b.channelFactory(channelFactory);
b.handler(new ChannelInitializer<DatagramChannel>() {
@Override
protected void initChannel(DatagramChannel ch) throws Exception {
ch.pipeline().addLast(DECODER, ENCODER, responseHandler);
}