public function WorkflowGetAvailabilityUsers($user_ids)
 {
     // $user_ids : IDType or this array
     $this->CheckAndSetHeader(__FUNCTION__);
     $reg_args["user_id"] = $this->getRegularArgs($user_ids, __FUNCTION__);
     $this->encodeString($reg_args);
     $results = parent::WorkflowGetAvailabilityUsers($reg_args);
     $this->methodClose();
     return $this->decodeString($results->user);
 }