code: async function batch ( url, batchUrl, options ) {
  
      options = _.omit ( options, ['url', 'batchUrl'] );
  
      const responses = await ( await fetch ( batchUrl, options ) ).json ();
  
      for ( let url in responses ) {
  
        if ( !responses.hasOwnProperty ( url ) ) continue;
  
        const response = responses[url],
              responseText = _.isString ( response ) ? response : JSON.stringify ( response );
  
        const request = {
          __fake: true,
          getAllResponseHeaders: () => '',
          status: 200,
          statusText: 'OK',
          responseURL: url,
          response: responseText,
          responseText
        };
  
        fetch.cache[url] = Promise.resolve ( fetch.request2response ( request ) );
  
      }
  
      return fetch.cache[url] || fetch ( url, options );
  
    }
docs: /* BATCH