protected void flagChannelForClose(Channel channel, ShutdownType shutdownType) {
        ConnectionCloseType.setForChannel(channel, ConnectionCloseType.DELAYED_GRACEFUL);
        ChannelPromise closePromise = channel.pipeline().newPromise();
        channel.attr(ConnectionCloseChannelAttributes.CLOSE_AFTER_RESPONSE).set(closePromise);
    }
TODO: Change this class to be an instance per-port.
So that then the configuration can be different per-port, which is need for the combined FTL/Cloud clusters.
<p>
User: michaels@netflix.com
Date: 3/6/17
Time: 12:36 PM
zuul-core/src/main/java/com/netflix/zuul/netty/server/ClientConnectionsShutdown.java