def METHOD_NAME():
    var = sc.arange('r', 6).fold('r', sizes={'a': 2, 'b': 3})
    assert sc.identical(sc.flatten(var, dims=['a', 'b'], to='f'), sc.arange('f', 6))
    assert sc.identical(sc.flatten(var, to='f'), sc.arange('f', 6))