docs: def get_gpg_home( appname, config_dir=None ):
      """
      Get the GPG keyring directory for a particular application.
      Return the path.
      """
      assert is_valid_appname(appname)
      config_dir = get_config_dir( config_dir )
      path = os.path.join( config_dir, "gpgkeys", appname )
      return path