code: def register_converter(self, converter, conv_type, conv_format=None, *, name=None):
          
          if name:
              self.app.url_map.converters[name] = converter
          self.spec.register_converter(converter, conv_type, conv_format)
docs: Register custom path parameter converter.
  
          :param BaseConverter converter: Converter
              Subclass of werkzeug's BaseConverter
          :param str conv_type: Parameter type
          :param str conv_format: Parameter format (optional)
          :param str name: Name of the converter. If not None, this name is used
              to register the converter in the Flask app.
              Example::
  
                  api.register_converter(
                      UUIDConverter, 'string', 'UUID', name='uuid')
                  @blp.route('/pets/{uuid:pet_id}')
                      # ...
                  api.register_blueprint(blp)
  
          This registers the converter in the Flask app and in the internal
          APISpec instance.
  
          Once the converter is registered, all paths using it will have
          corresponding path parameter documented with the right type and format.
          The `name` parameter need not be passed if the converter is already
          registered in the app, for instance if it belongs to a Flask extension
          that already registers it in the app.