@Override
  public void setClusterSecretKey(byte[] clusterSecretKey) {
    if (encrypt != null) {
      if (logger.isDebugEnabled()) {
        logger.debug("Setting cluster key");
      }
      encrypt.setClusterKey(clusterSecretKey);
    }
  }
returns the handler that should process the given message. The default handler is the
membership manager
geode-membership/src/main/java/org/apache/geode/distributed/internal/membership/gms/messenger/JGroupsMessenger.java