Example: ```python if TYPE_CHECKING: from _typeshed import StrPath def foo(path: StrPath) -> StrPath: return path ``` Output (fails a build on read the docs): ```none WARNING: Failed guarded type import with ModuleNotFoundError("No module named '_typeshed'") ``` Stubs for `_typeshed`: https://github.com/python/typeshed/tree/main/stdlib/_typeshed