@Override
  protected void addSubscriptionInternal(
      String sessionId, String subsId, String destination, Message<?> message) {

    Expression expression = getSelectorExpression(message.getHeaders());
    this.subscriptionRegistry.addSubscription(sessionId, subsId, destination, expression);
    this.destinationCache.updateAfterNewSubscription(destination, sessionId, subsId);
  }
Return the name for the selector header.
@since 4.2
ambari-server/src/main/java/org/apache/ambari/server/agent/stomp/AmbariSubscriptionRegistry.java