Multiple Vincent/Vega charts in a popup?

I'm trying to add two Vincent bar charts in a popup using Vega, one on top of the other. The two methods below are not working:

# Adding both charts to add_child: This only renders the first chart
m.add_child( folium.CircleMarker(
        location = [df['latitude'], df['longitude']],
        popup = folium.Popup(max_width = 450).add_child(chart1, chart2)
  ))

# Method-chaining: This only renders the second chart
m.add_child( folium.CircleMarker(
        location = [df['latitude'], df['longitude']],
        popup = folium.Popup(max_width = 450).add_child(chart1, name = 'c1').add_child(chart2, name = 'c2')
    ) )

Is there a way to accomplish this?

まず、issue内の2つの例から Popup.add_child を追跡し、popupの子要素がどのようにレンダリングされるかを調べます。1つのpopupで、1つ目または2つ目のチャートだけでなく、両方のVincent/Vegaチャートが確実に表示されれば作業は完了です。