def import_third_party(modname: str) -> tuple[ModuleType, bool]:
    """Import a third-party module we need, but might not be installed.

    This also cleans out the module after the import, so that coverage won't
    appear to have imported it.  This lets the third party use coverage for
    their own tests.

    Arguments:
        modname (str): the name of the module to import.

    Returns:
        The imported module, and a boolean indicating if the module could be imported.

    If the boolean is False, the module returned is not the one you want: don't use it.

    """
    with sys_modules_saved():
        try:
            return importlib.import_module(modname), True
        except ImportError:
            return sys, False
Import a third-party module we need, but might not be installed.

    This also cleans out the module after the import, so that coverage won't
    appear to have imported it.  This lets the third party use coverage for
    their own tests.

    Arguments:
        modname (str): the name of the module to import.

    Returns:
        The imported module, and a boolean indicating if the module could be imported.

    If the boolean is False, the module returned is not the one you want: don't use it.

    
coverage/misc.py