static function get_profile_document($userId){
        $user = Pluf_Shortcuts_GetObjectOr404('User', $userId);
        // Find collection profile
        $collection = Collection_Shortcuts_GetCollectionByName(User_Constants::PROFILE_COLLECTION_NAME);
        if($collection === null){
            $collection = new Collection_Collection();
            $collection->name = User_Constants::PROFILE_COLLECTION_NAME;
            $collection->title= 'Collection for saving profile of users';
            $collection->create();
        }
        $cprofile = new Profile();
        $cprofile = $cprofile->getOne('user = ' . $userId);
        if($cprofile === null){
            // create cprofile and document for profile of user
            $document = new Collection_Document();
            $document->collection = $collection;
            $document->create();
            $cprofile = new Profile();
            $cprofile->user = $user;
            $cprofile->profile = $document;
            $cprofile->create();
        }
        $profileDoc = new Collection_Document($cprofile->profile);
        return $profileDoc;
    }