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
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
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