onUnsubscription(roomId) {
    const messageId = this.publisher.sendUnsubscription(roomId);

    debug(
      "[%s] Broadcasting realtime unsubscription on room %s (message: %d)",
      this.nodeId,
      roomId,
      messageId,
    );

    this.fullState.removeRealtimeSubscription(roomId, this.nodeId, messageId);
  }
Triggered when a user unsubscribes from a room

@param  {string} roomId
@return {void}