private function prepareRequestParams($obj_request)
    {
        $obj_params = $obj_request->mutableParams();
        $obj_spec = $obj_params->mutableIndexSpec()->setName($this->str_index_name);
        if(null !== $this->str_namespace) {
            $obj_spec->setNamespace($this->str_namespace);
        }
        return $obj_params;
    }