publish(request) {
    const rooms = this._test(request);

    if (rooms.length === 0) {
      return Bluebird.resolve(null);
    }

    return this.notifyDocument(rooms, request, "in", "publish", {
      _id: request.input.args._id,
      _source: request.input.body,
    });
  }
Publish the content of the provided request to listening subscribers

@param {Request} request
@returns {Promise.<Object>}