def adata():
    adata = ad.AnnData(np.zeros((100, 100)))
    adata.obsm["o"] = np.zeros((100, 50))
    adata.varm["o"] = np.zeros((100, 50))
    return adata
def test_impl():
            A = np.array([1., 2., 3.])
            A[0] = np.nan
            df = pd.DataFrame({'A': A})
            B = df.A.fillna(5.0)
            return B.sum()