def autouse_pytester(pytester: Pytester) -> None:
    """
    Fixture to make pytester() being autouse for all tests in this module.

    pytester makes sure to restore sys.path to its previous state, and many tests in this module
    import modules and change sys.path because of that, so common module names such as "test" or "test.conftest"
    end up leaking to tests in other modules.

    Note: we might consider extracting the sys.path restoration aspect into its own fixture, and apply it
    to the entire test suite always.
    """

    Fixture to make pytester() being autouse for all tests in this module.

    pytester makes sure to restore sys.path to its previous state, and many tests in this module
    import modules and change sys.path because of that, so common module names such as "test" or "test.conftest"
    end up leaking to tests in other modules.

    Note: we might consider extracting the sys.path restoration aspect into its own fixture, and apply it
    to the entire test suite always.
    
testing/test_pathlib.py