private static void notifyHandlers(
            ChannelHandlerContext ctx,
            StatusCategory nfStatus,
            HttpResponseStatus status,
            String reason,
            HttpRequest request) {
        RequestRejectedEvent event = new RequestRejectedEvent(request, nfStatus, status, reason);
        // Send this from the beginning of the pipeline, as it may be sent from the ClientRequestReceiver.
        ctx.pipeline().fireUserEventTriggered(event);
    }
Switches on the rejection type to decide how to reject the request and or close the conn.

@param ctx                   the channel handler processing the request
@param rejectionType         the type of rejection
@param nfStatus              the status to use for metric reporting
@param reason                the reason for rejecting the request.  This is not sent back to the client.
@param request               the request that is being rejected.
@param injectedLatencyMillis optional parameter to delay sending a response. The reject notification is still
                             sent up the pipeline.
@param rejectedCode          the HTTP code to send back to the client.
@param rejectedBody          the HTTP body to be sent back.  It is assumed to be of type text/plain.
@param rejectionHeaders      additional HTTP headers to add to the rejection response
zuul-core/src/main/java/com/netflix/netty/common/throttle/RejectionUtils.java