def get_converter(
        self,
        variable_name: str,
        converter_name: str,
        args: tuple[t.Any, ...],
        kwargs: t.Mapping[str, t.Any],
    ) -> BaseConverter:
        """Looks up the converter for the given parameter.

        .. versionadded:: 0.9
        """
        if converter_name not in self.map.converters:
            raise LookupError(f"the converter {converter_name!r} does not exist")
        return self.map.converters[converter_name](self.map, *args, **kwargs)
Looks up the converter for the given parameter.

        .. versionadded:: 0.9
        
src/werkzeug/routing/rules.py