How should you properly and correctly avoid calling setState after a StatefulWidget's own associated State object has genuinely already been disposed of, such as after an asynchronous operation genuinely completes following a user having already navigated away?

Since an asynchronous operation genuinely can take some meaningful amount of time to actually complete, and the widget that originally initiated that particular operation could genuinely have already been fully disposed of sometime during that same waiting period, such as if a user had already navigated away from that specific screen entirely, calling setState directly after that genuinely completed asynchronous operation without first properly checking whether that particular State object is still genuinely currently mounted can throw a genuine runtime exception, and properly checking the mounted property immediately before actually calling setState correctly avoids this particular common, quite easy to accidentally make mistake.

Future<void> loadData() async {
  final data = await fetchData();
  if (mounted) {
    setState(() => _data = data);
  }
}