Symfony\Cmf\Bundle\RoutingBundle\Model\Route::isBooleanOption PHP Method

    protected function isBooleanOption($name)
    {
        return in_array($name, array('add_format_pattern', 'add_locale_pattern'));
    }

 /**
  * {@inheritdoc}
  */
 protected function isBooleanOption($name)
 {
     return $name === 'add_trailing_slash' || parent::isBooleanOption($name);
 }