code: def _default_temporary_directory(self, prefix):
      
      try:
        self.temporary_file = tempfile.NamedTemporaryFile(prefix=prefix)
  
      except OSError as err: # pragma: no cover
        logger.critical('Cannot create a system temporary directory: '+repr(err))
        raise securesystemslib.exceptions.Error(err)
docs: __init__ helper.