export function useMyHook() {
  // flags for purity:
  const abortControllerRef = useRef(new AbortController());
  // also flags: pattern from https://react.dev/reference/react/useRef#avoiding-recreating-the-ref-contents
  const abortControllerRef2 = useRef<AbortController>(null);
  if (abortControllerRef2.current === null) {
    abortControllerRef2.current = new AbortController();
  }
  // Does not flag: equivalent useState initializer:
  const abortController = useState(() => new AbortController());
}