combine with grouped dataframe

[bicepjai]

Is there a syntax to work with whole grouped dataframe instead of just one or more columns ?
syntax to deal with examples provided dataframes-split_apply_combine like

combine(gdf) do df
    (m = mean(df.PetalLength), s² = var(df.PetalLength))
end

[bicepjai]

i was ignorant. answer in the same page. dataframes-split_apply_combine