code: @SuppressWarnings("unchecked")
      private Hashtable getAutoTransferringHeaders()
      {
          Hashtable headers = (Hashtable)_req.getAttribute(AUTO_XFER_HEADERS_ATTR);
          if (headers == null)
          {
              headers = new Hashtable();
              _req.setAttribute(AUTO_XFER_HEADERS_ATTR, headers);
          }
          return headers;
      }
docs: Get the headers that are designated as auto-transfer.