code: def _GetSubFileEntries(self):
      
      if self._directory is None:
        self._directory = self._GetDirectory()
  
      if self._directory:
        for path_spec in self._directory.entries:
          yield self._file_system.GetFileEntryByPathSpec(path_spec)
docs: Retrieves sub file entries.
  
      Yields:
        FakeFileEntry: a sub file entry.