docs: def register(util_type, registry=_utils):
      """
      Crude, local registration decorator for a crude local registry of
      all utilities local to this module.
      """
  
      def marker(f):
          mark = util_type + '_'
          if not f.__name__.startswith(mark):
              raise TypeError(
                  'not registering %s to %s' % (f.__name__, util_type))
          registry[util_type][f.__name__[len(mark):]] = f
          return f
      return marker