public function BulletinGetDraftTopicVersions($start, $end = false, $topic_item = false)
 {
     // $start : UNIX timestamp
     // $end   : UNIX timestamp (optional)
     // $topic_item : ItemVersionType or this array or false (optional)
     $this->CheckAndSetHeader(__FUNCTION__);
     $reg_args = array();
     $reg_args["start"] = gmdate(W3C_DATETIME_FORMAT, $start);
     if ($end !== false) {
         $reg_args["end"] = gmdate(W3C_DATETIME_FORMAT, $end);
     }
     if ($topic_item !== false) {
         $reg_args["topic_item"] = $this->getRegularArgs($topic_item, __FUNCTION__, "CbgrnItemVersionType");
     }
     $this->encodeString($reg_args);
     $results = parent::BulletinGetDraftTopicVersions($reg_args);
     $this->methodClose();
     return $this->RetvalConvertArray($results->topic_item);
     // returns array of stdClass
 }