在useEffect cleanup函数执行之前，获取“Can‘t perform a React state update on an unmounted”

import React, { useEffect, useState } from 'react';

const ExampleComponent = () => {
  const [data, setData] = useState(null);

  useEffect(() => {
    let isMounted = true;

    fetchData().then(response => {
      if (isMounted) {
        setData(response);
      }
    });

    return () => {
      isMounted = false;
    };
  }, []);

  return (
    <div>
      {data ? (
        <p>{data}</p>
      ) : (
        <p>Loading...</p>
      )}
    </div>
  );
};

const fetchData = () => {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve('Data fetched');
    }, 1000);
  });
};

export default ExampleComponent;