off(event, handler) {
    this._transport.unbind(event, handler);

    return this;
  }
/**
   * Simple proxy method for unbinding events
   *
   * @param {String} event The name of the event to unbind from
   * @param {Function} handler The function to unbind from the event
   * @returns {PBSMessageAPI}
   */
Simple proxy method for unbinding events
@param {String} event The name of the event to unbind from
@param {Function} handler The function to unbind from the event
@returns {PBSMessageAPI}
Simple proxy method for unbinding events @param { String } event The name of the event to unbind from @param { Function } handler The function to unbind from the event @returns { PBSMessageAPI }
off(event, handler) {
    this._transport.unbind(event, handler);
    return this;
  }
off ( event , handler ) { this . _transport . unbind ( event , handler ) ; return this ; }
Simple proxy method for unbinding events
 @param {String} event The name of the event to unbind from
 @param {Function} handler The function to unbind from the event
 @returns {PBSMessageAPI}
Simple proxy method for unbinding events @param { String } event The name of the event to unbind from @param { Function } handler The function to unbind from the event @returns { PBSMessageAPI }