The above example is intended to demonstrate drawing a simple Sankey diagram using v4 of d3.js. It uses Jason Davies' version of the Sankey plugin.
This is one of the code samples for the update to the book D3 Tips and Tricks to version 4 of d3.js.
forked from d3noob's block: IVR from JSON
https://d3js.org/d3.v4.min.js
https://d3js.org/d3-scale-chromatic.v1.min.js