How to use the fontmake.instantiator.InstantiatorError function in fontmake

def test_raise_failed_glyph_interpolation(data_dir):
    designspace = designspaceLib.DesignSpaceDocument.fromfile(
        data_dir / "DesignspaceBrokenTest" / "DesignspaceTest.designspace"
    )
    generator = fontmake.instantiator.Instantiator.from_designspace(designspace)

    with pytest.raises(
        fontmake.instantiator.InstantiatorError, match="Failed to generate instance"
    ):
        for instance in designspace.instances:
            instance.font = generator.generate_instance(instance)