def METHOD_NAME(self, file_regression):
    path = DIR / Path('files/mod_pot/test1/')
    pot = os.fspath(path / 'pot')
    out_pot = os.fspath(path / 'pot_new')
    neworder = [0, 1, 2]
    # test 1: neworder_potential standard
    modify_potential().neworder_potential(pot, out_pot, neworder)
    with open(out_pot, encoding='utf-8') as f:
        txt = f.read().strip()
    file_regression.check(txt)