Add a callback handler for ephemeral events going to this room.

        Args:
            callback (func(room, event)): Callback called when an ephemeral event arrives.
            event_type (str): The event_type to filter for.
        Returns:
            uuid.UUID: Unique id of the listener, can be used to identify the listener.

def add_ephemeral_listener(self, callback, event_type=None):
        """Add a callback handler for ephemeral events going to this room.

        Args:
            callback (func(room, event)): Callback called when an ephemeral event arrives.
            event_type (str): The event_type to filter for.
        Returns:
            uuid.UUID: Unique id of the listener, can be used to identify the listener.
        """
        listener_id = uuid4()
        self.ephemeral_listeners.append(
            {
                'uid': listener_id,
                'callback': callback,
                'event_type': event_type
            }
        )
        return listener_id