At this stage, we are only able to check that the
subscription works on js side: it confirms that
the nim node is considered as subscribing to the same
topic.
At the moment we do not assert that we publish messages over waku relay
protocol (not sure this assertion is possible).
By asserting we do not register any sub (pubsub, gossipsub, floodsub)
protocols, we can be (more) confident that this
protocols are not be used behind the scenes.