https://unpkg.com/babel-polyfill@6.26.0/dist/polyfill.js
https://unpkg.com/custom-event-polyfill@0.3.0/custom-event-polyfill.js
https://cdnjs.cloudflare.com/ajax/libs/document-register-element/1.8.0/document-register-element.js
https://unpkg.com/babel-standalone@6/babel.min.js
https://unpkg.com/d3@5.5.0
https://unpkg.com/d3fc@14.0.41