Pimcore\Model\User\Permission\Definition::getByKey PHP Method

    public static function getByKey($permission)
    {
        if (!$permission) {
            throw new \Exception("No permisson defined.");
        }
        $list = new Definition\Listing();
        $list->setCondition("`key`=?", [$permission]);
        $list->setLimit(1);
        $permissionDefinition = $list->load();
        if ($permissionDefinition[0]) {
            return $permissionDefinition[0];
        }
    }