Scalr\Acl\Resource\Definition::has PHP Method

    public static function has($resourceId)
    {
        $list = self::getAll();
        return isset($list[$resourceId]);
    }

 protected function validateBefore1($stage)
 {
     return defined('Scalr\\Acl\\Acl::RESOURCE_WEBHOOKS_ENVIRONMENT') && Definition::has(Acl::RESOURCE_WEBHOOKS_ENVIRONMENT);
 }