docs: public static <T> T with(HttpRequest request, Supplier<T> callable) {
          HttpRequest existing = REQUEST.get();
          boolean isSet = false;
          try {
              if (request != existing) {
                  isSet = true;
                  REQUEST.set(request);
              }
              return callable.get();
          } finally {
              if (isSet) {
                  REQUEST.remove();
              }
          }
      }