docs: def GetUrnHashEntry(urn, token=None):
    """Returns an `rdf_crypto.Hash` instance for given URN of an AFF4 file."""
    if data_store.RelationalDBEnabled():
      client_id, vfs_path = urn.Split(2)
      path_type, components = rdf_objects.ParseCategorizedPath(vfs_path)
  
      path_info = data_store.REL_DB.ReadPathInfo(client_id, path_type, components)
      return path_info.hash_entry
    else:
      with aff4.FACTORY.Open(urn, token=token) as fd:
        return GetFileHashEntry(fd)