def test_invalid_scalar_index(adata, index):
    # https://github.com/theislab/anndata/issues/619
    with pytest.raises(IndexError, match=r".*index.* out of range\."):
        _ = adata[index]
def test_impl(n):
            S1 = pd.Series(np.ones(n))
            S2 = pd.Series(np.random.ranf(n))
            df = pd.DataFrame({'A': S1, 'B': S2})
            return df.A.sum()