The examples here listen to push events on the body which are thrown by the push_kit service.
The push_kit service subscribes to a topic/filter on an exchange and address as configured in the meta tags.
In this example this is: ws://localhost:15674/ws/exchange/patternslib and a topic filter of push_marker.
If a message is sent through rabbitmq on the "patternslib" exchange on the push_marker topic containing the message "message_counter" or "message_counter2" the messages badge below will be updated.