code: def observe_events(client)
        return unless enable_listener?
        queue = create_queue(client)
        client.subscribe(queue) do |message|
          event = Event.parse(message)
          handle_event(event)
        end
      end
docs: Create or attach to a queue on the specified exchange. When an event message that matches the observer's routing keys
   is received, parse the event and call handle_event on same.
   @param [Isimud::Client] client client instance
   @return queue or consumer object
   @see BunnyClient#subscribe
   @see TestClient#subscribe