def METHOD_NAME(tmp_path):
    output = tmp_path / "output.h5mu"
    df = pd.DataFrame([[1, 2, 3], [4, 5, 6]], index=["obs1", "obs2"], columns=["var1", "var2", "var3"])
    obs = pd.DataFrame([["A", "sample1"], ["B", "sample2"]], index=df.index, columns=["Obs", "sample_id"])
    var = pd.DataFrame([["a", "sample1"], ["b", "sample2"], ["c", "sample1"]],
                        index=df.columns, columns=["Feat", "sample_id_var"])
    ad1 = AnnData(df, obs=obs, var=var)
    var2 = pd.DataFrame(["d", "e", "g"], index=df.columns, columns=["Feat"])
    obs2 = pd.DataFrame(["C", "D"], index=df.index, columns=["Obs"])
    ad2 = AnnData(df, obs=obs2, var=var2)
    mudata = MuData({'mod1': ad1, 'mod2': ad2})
    mudata.write_h5mu(output)
    return output, mudata