/**
  * Get parent subdomain and set some properties
  * from parent domain.
  *
  * @param Subdomain $subdomain
  *
  * @return Subdomain
  */
 public static function transformAliasSubdomain(Subdomain $subdomain)
 {
     if ($subdomain->getParent() !== null) {
         $domain = self::transformAliasDomain($subdomain->getDomain());
         $parent = clone $subdomain->getParent();
         $parent->setDomain($domain)->setSubdomain($subdomain->getSubdomain())->setCertificate($subdomain->getCertificate());
         return $parent;
     }
     return $subdomain;
 }