public static function validate_class_inheritance(array $relation): array
    {
        return array_filter($relation, function($className)
        {
            if (
                ClassInfo::exists($className)
                && (is_a(singleton($className), ElementBase::class))
            ) {
                return $className;
            }
            user_error('Your element needs to extend from ' . ElementBase::class, E_USER_WARNING);
        });
    }