def _map_samples(
        self,
        sample_collection: SampleCollection[T],
        iter_fcn: Callable[
            [SampleCollection[T]], Iterable[Tuple[bson.ObjectId, U]]
        ],
        map_fcn: Callable[[U], R],
        *,
        progress: Union[bool, Literal["workers"], None],
        skip_failures: bool,
    ) -> Iterator[
        Tuple[bson.ObjectId, Union[Exception, None], Union[R, None]]
    ]:
        """Applies map function to each sample and returns an iterator
        of the results."""
Applies map function to each sample and returns an iterator
        of the results.
fiftyone/core/map/mapper.py