// WARNING! async function must not be passed directly!//useEffect(async () => {//
     const response = await fetch(`https://www.reddit.com/r/${subreddit}.json`);//
     const json = await response.json();//…//}, []);React.useEffect(() => {
   let ignore = false;
   async function fetchProduct() {
      const response = await fetch('http://myapi/product/' + productId);
      const json = await response.json();
      if (!ignore) setProduct(json);
   }
   fetchProduct();
   return () => { ignore = true };}, [productId]);