def _EntriesGenerator(self):
    """Retrieves directory entries.

    Since a directory can contain a vast number of entries using
    a generator is more memory efficient.

    Yields:
      APFSContainerPathSpec: a path specification.
    """
    # Only the virtual root file has directory entries.
    volume_index = apfs_helper.APFSContainerPathSpecGetVolumeIndex(
        self.path_spec)
    if volume_index is not None:
      return

    location = getattr(self.path_spec, 'location', None)
    if location is None or location != self._file_system.LOCATION_ROOT:
      return

    fsapfs_container = self._file_system.GetAPFSContainer()

    for volume_index in range(0, fsapfs_container.number_of_volumes):
      yield apfs_container_path_spec.APFSContainerPathSpec(
          location='/apfs{0:d}'.format(volume_index + 1),
          volume_index=volume_index, parent=self.path_spec.parent)
Retrieves directory entries.

    Since a directory can contain a vast number of entries using
    a generator is more memory efficient.

    Yields:
      APFSContainerPathSpec: a path specification.