public boolean serverAuthenticationSessionExpired(long nowNanos) {
        Long serverSessionExpirationTimeNanos = authenticator.serverSessionExpirationTimeNanos();
        return serverSessionExpirationTimeNanos != null && nowNanos - serverSessionExpirationTimeNanos > 0;
    }
Return true if this is a server-side channel and the given time is past the
session expiration time, if any, otherwise false

@param nowNanos
           the current time in nanoseconds as per {@code System.nanoTime()}
@return true if this is a server-side channel and the given time is past the
        session expiration time, if any, otherwise false
clients/src/main/java/org/apache/kafka/common/network/KafkaChannel.java