def remove_arg(ap: argparse.ArgumentParser,
option: str) -> argparse.ArgumentParser:
"""
Removes an argument from an `ArgumentParser`.
Note: uses a non-public behavior of the `argparse` API.
"""
ap = copy.deepcopy(ap)
action = list(filter(lambda a: option in a.option_strings, ap._actions))[0]
ap._handle_conflict_resolve(None,
[(option, action)]) # type: ignore[arg-type]
return ap
