Method extend

src/flask/sansio/blueprints.py:380–386

(
            bp_dict: dict[ft.AppOrBlueprintKey, list[t.Any]],
            parent_dict: dict[ft.AppOrBlueprintKey, list[t.Any]],
        )

    def _merge_blueprint_funcs(self, app: App, name: str) -> None:
        def extend(
            bp_dict: dict[ft.AppOrBlueprintKey, list[t.Any]],
            parent_dict: dict[ft.AppOrBlueprintKey, list[t.Any]],
        ) -> None:
            for key, values in bp_dict.items():
                key = name if key is None else f"{name}.{key}"
                parent_dict[key].extend(values)

        for key, value in self.error_handler_spec.items():
            key = name if key is None else f"{name}.{key}"