Energy Force chart showing an error on the Misc Charts example dashboard

[yousoph]

How to reproduce the bug

1. Click on Dashboards
2. Click the Misc Charts example dashboard

Expected results

All charts on the example dashboard load without errors

Actual results

The Energy Force chart shows an error

Screenshots

Environment

(please complete the following information):

• superset version: master
• python version: python --version
• node.js version: node -v

Checklist

Make sure to follow these steps before submitting your issue - thank you!

• I have checked the superset logs for python stacktraces and included it here as text if there are any.
• I have reproduced the issue with at least the latest released version of superset.
• I have checked the issue tracker for the same issue and I haven't found one similar.

[junlincc]

thanks for reporting. FYI.
Cause and solution can both found in the comment. We also flag this PR as risk a couple times.
#13111

[yousoph]

ah, thanks