code: function onRequestError(error, result, endCallback) {
        result.currentRetries++;
        async.parallel([
          async.apply(recrawlError, error, result),
          async.apply(retrySameUrl,error, result)
        ],function(error){
            endCallback(error);
        });
  
    }
docs: Callback used when a Http request generates an error.
  1.Inform plugins (if exists)
  2. Retry the same request/URL
  
  @param The Http error
  @param the crawl options
  @param the HTTP response
  @param callback()