def METHOD_NAME(mocked_smart_open, files):
    """Test existence of files across supported locations"""
    File(files["path"]).exists()
    mocked_smart_open.assert_called()
    kwargs = mocked_smart_open.call_args.kwargs
    args = mocked_smart_open.call_args.args
    if kwargs["transport_params"]:
        assert isinstance(kwargs["transport_params"]["client"], files["instance"])
    assert files["path"] == args[0]