code: public static @Nullable GrailsWebRequest lookup(HttpServletRequest request) {
          GrailsWebRequest webRequest = (GrailsWebRequest) request.getAttribute(GrailsApplicationAttributes.WEB_REQUEST);
          return webRequest == null ? lookup() : webRequest;
      }
docs: Looks up the GrailsWebRequest from the current request.
  @param request The current request
  @return The GrailsWebRequest