public function save($resourceKey, $resourceVersion = false, $fileExtension = '')
 {
     $dirname = 'mainio_minco_combined_assets';
     $url = MINCO_RESOURCES_SAVE_DIR_REL . '/' . $dirname;
     $saveDir = MINCO_RESOURCES_SAVE_DIR . '/' . $dirname;
     Loader::library("minco_file_writer", "mainio_minco");
     $file = MincoFileWriter::writeStatic($resourceKey, $resourceVersion, $fileExtension, $saveDir);
     return $url . '/' . $file;
 }