docs: protected boolean beginRequest() {
          int oldState, newState;
          for (;;) {
              oldState = state;
              if ((oldState & CLOSED) != 0) {
                  return false;
              }
              newState = oldState + 1;
              if (newState == Integer.MAX_VALUE) {
                  return false;
              }
              if (stateUpdater.compareAndSet(this, oldState, newState)) {
                  return true;
              }
          }
      }