def get_min_depth(self, room_id):
        return self.runInteraction(
            "get_min_depth",
            self._get_min_depth_interaction,
            room_id,
        )
For hte given room, get the minimum depth we have seen for it.
dataset/ETHPy150Open matrix-org/synapse/synapse/storage/event_federation.py/EventFederationStore.get_min_depth