docs: def init_argparser_loaderplugin_registry(
              self, argparser, default=None, help=(
                  'the name of the registry to use for the handling of loader '
                  'plugins that may be loaded from the given Python packages'
              )):
          """
          Default helper for setting up the loaderplugin registries flags.
  
          Note that this is NOT part of the init_argparser due to
          implementation specific requirements.  Subclasses should
          consider modifying the default value help message to cater to the
          toolchain it encapsulates.
          """
  
          argparser.add_argument(
              '--loaderplugin-registry', default=default,
              dest=CALMJS_LOADERPLUGIN_REGISTRY_NAME, action='store',
              metavar=metavar('registry'),
              help=help,
          )