/**
  * Constructor
  * @param int[] $namespaces Namespace numbers to search
  * @param User|null $user
  * @param string $index Base name for index to search from, defaults to wfWikiId()
  * @param string $interwiki Interwiki prefix we're searching
  */
 public function __construct(Connection $connection, array $namespaces, User $user = null, $index, $interwiki)
 {
     parent::__construct($connection, 0, self::MAX_RESULTS, null, $namespaces, $user, $index);
     $this->interwiki = $interwiki;
     // Only allow core namespaces. We can't be sure any others exist
     if ($this->namespaces !== null) {
         $this->namespaces = array_filter($namespaces, function ($namespace) {
             return $namespace <= 15;
         });
     }
 }