public function parse(FeedsSource $source, FeedsFetcherResult $fetcher_result)
 {
     //grab the raw data from the batch
     $raw_data = $fetcher_result->getRaw();
     $file_path = $fetcher_result->getFilePath();
     //parses the extension correctly
     $file_path = pathinfo($file_path);
     $file_type = $file_path['extension'];
     //declares new variables
     $parser_result = new FeedsParserResult();
     $items = array();
     //switches based on file type. data within the files are then passed over to the handlers
     switch ($file_type) {
         case 'ris':
             $items = $this->_getty_bib_ris_handler($raw_data);
             break;
         case 'rdf':
             $items = $this->_getty_bib_rdf_handler($raw_data);
             break;
     }
     $parser_result->items = $items;
     return $parser_result;
 }