code: @SuppressWarnings("unchecked")
    private Object fireEvent(Request request, PageBook.Page page, Object instance)
        throws IOException {
      final String method = request.method();
      final String pathInfo = request.path();
  
      return page.doMethod(method.toLowerCase(), instance, pathInfo, request);
    }
docs: We're sure the request parameter map is a Map<String, String[]>