public function unregisterEngine($identifier)
    {
        $result = false;

        if(strpos($identifier, '.') !== false )
        {
            $identifier = $this->getIdentifier($identifier);
            $class      = $this->getObject('manager')->getClass($identifier);

            if(!$class || !array_key_exists('KTemplateEngineInterface', class_implements($class)))
            {
                throw new UnexpectedValueException(
                    'Engine: '.$identifier.' does not implement KTemplateEngineInterface'
                );
            }

            $types = call_user_func(array($class, 'getFileTypes'));/*$class::getFileTypes();*/

        }
        else $types = (array) $identifier;

        if (!empty($types))
        {
            foreach($types as $type)
            {
                if($this->isRegistered($type)) {
                    unset($this->__engines[$type]);
                }
            }
        }

        return $result;
    }