def test_vl_spec_for_band_edge_values():

    band = api.Band()

    try:
        band.size = -1
        raise Exception('Should have thrown for illegal size min value.')
    except TraitError:
        pass

    try:
        band.padding = -1
        raise Exception('Should have thrown for illegal padding min value.')
    except TraitError:
        pass
Check edge values
dataset/ETHPy150Open ellisonbg/altair/altair/tests/test_api.py/test_vl_spec_for_band_edge_values