code: public function init()
      {
          parent::init();
          if (empty($this->mask) && empty($this->clientOptions['alias'])) {
              throw new InvalidConfigException("Either the 'mask' property or the 'clientOptions[\"alias\"]' property must be set.");
          }
      }
docs: Initializes the widget.
  
  @throws InvalidConfigException if the "mask" property is not set.