js/swifflegrid.js is built with Babel (https://babeljs.io/), which injects a small number
of MIT-licensed runtime helper functions into the compiled output so the code also runs on
older browsers.

Babel
Copyright (c) 2014-present Sebastian McKenzie and other contributors
Released under the MIT license
https://github.com/babel/babel/blob/main/LICENSE

No other third-party code is bundled in this file. The full, human-readable source is
included with this plugin under published-source/webcomponent/main.js — see
published-source/README.txt.
