def METHOD_NAME(df):
    res = Description(df)
    assert isinstance(res.frame, pd.DataFrame)
    assert isinstance(res.numeric, pd.DataFrame)
    assert isinstance(res.categorical, pd.DataFrame)
    assert isinstance(res.summary(), SimpleTable)
    assert isinstance(res.summary().as_text(), str)
    assert "Descriptive" in str(res)
    res = Description(df.a)
    assert isinstance(res.frame, pd.DataFrame)
    assert isinstance(res.numeric, pd.DataFrame)
    assert isinstance(res.categorical, pd.DataFrame)
    assert isinstance(res.summary(), SimpleTable)
    assert isinstance(res.summary().as_text(), str)
    assert "Descriptive" in str(res)
    res = Description(df.b)
    assert isinstance(res.frame, pd.DataFrame)
    assert isinstance(res.numeric, pd.DataFrame)
    assert isinstance(res.categorical, pd.DataFrame)
    assert isinstance(res.summary(), SimpleTable)
    assert isinstance(res.summary().as_text(), str)
    assert "Descriptive" in str(res)