This is a test for adjusting the link function in sankey.js to account for the following case: If two connected nodes are at the same x position, their link should be an S-like curve.
It just takes to add one additional line in the link function of sankey.js.
This is based on 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: Sankey Diagram with curved vertical links