def _get_exporter(self, args: argparse.Namespace) -> PrometheusExporter:
        """Return a :class:`PrometheusExporter` configured with args."""
        exporter = PrometheusExporter(
            self.name, self.description, args.host, args.port, self.registry)
        exporter.app.on_startup.append(self.on_application_startup)
        exporter.app.on_shutdown.append(self.on_application_shutdown)
        return exporter