def last_written_time(self):
    """dfdatetime.DateTimeValues: last written time or None."""
    if not self._registry_key and self._registry:
      self._GetKeyFromRegistry()

    if not self._registry_key:
      return None

    return self._registry_key.last_written_time
def last_written_time ( self ) : if not self . _registry_key and self . _registry : self . _GetKeyFromRegistry ( ) if not self . _registry_key : return None return self . _registry_key . last_written_time
dfdatetime.DateTimeValues: last written time or None.