def METHOD_NAME(
    decoy: Decoy,
    mock_geometry: ModuleGeometry,
    subject: LegacyMagneticModuleCore,
) -> None:
    """It should raise if no labware is loaded."""
    decoy.when(mock_geometry.labware).then_return(None)
    with pytest.raises(ValueError):
        subject.engage_to_labware()