protected void removeIdleStateHandler(PooledConnection conn) {
        DefaultClientChannelManager.removeHandlerFromPipeline(
                DefaultClientChannelManager.IDLE_STATE_HANDLER_NAME,
                conn.getChannel().pipeline());
    }
function to run when a connection is acquired before returning it to caller.
zuul-core/src/main/java/com/netflix/zuul/netty/connectionpool/PerServerConnectionPool.java