def GetRootFileEntry(self):
    """Retrieves the root file entry.

    Returns:
      DataRangeFileEntry: a file entry or None if not available.
    """
    path_spec = data_range_path_spec.DataRangePathSpec(
        range_offset=self._range_offset,
        range_size=self._range_size,
        parent=self._path_spec.parent)
    return self.GetFileEntryByPathSpec(path_spec)