protected void logSecurityTokenVerificationFail() {
        logger.warn("Push secure token verification failed");
    }
Serves "/push" URL that is used by the backend to POST push messages to a given Zuul instance. This URL handler
MUST BE accessible ONLY from RFC 1918 private internal network space (10.0.0.0 or 172.16.0.0) to guarantee that
external applications/agents cannot push messages to your client. In AWS this can typically be achieved using
correctly configured security groups.

Author: Susheel Aroskar
Date: 5/14/18
zuul-core/src/main/java/com/netflix/zuul/netty/server/push/PushMessageSender.java