public static function getClassname($type)
    {
        if (!isset(self::$__classnames[$type])) {
            $classname = 'AnDomainAttribute'.ucfirst($type);
            $classname = class_exists($classname) ?  $classname : $type;
            if (!is($classname, 'AnDomainAttributeInterface')) {
                throw new AnDomainExceptionType($classname.' must implements AnDomainAttributeInterface');
            }
            self::$__classnames[$type] = $classname;
        }

        return self::$__classnames[$type];
    }