docs: public void doResources(StaplerRequest req, StaplerResponse rsp) throws IOException, ServletException {
          String path = req.getRestOfPath();
          // cut off the "..." portion of /resources/.../path/to/file
          // as this is only used to make path unique (which in turn
          // allows us to set a long expiration date
          path = path.substring(path.indexOf('/',1)+1);
  
          int idx = path.lastIndexOf('.');
          String extension = path.substring(idx+1);
          if(ALLOWED_RESOURCE_EXTENSIONS.contains(extension)) {
              URL url = pluginManager.uberClassLoader.getResource(path);
              if(url!=null) {
                  long expires = MetaClass.NO_CACHE ? 0 : TimeUnit.DAYS.toMillis(365);
                  rsp.serveFile(req,url,expires);
                  return;
              }
          }
          rsp.sendError(HttpServletResponse.SC_NOT_FOUND);
      }