Exploration of bar code chart example, from Chapter 2 of Mastering D3.

It is derived from Mike Bostock's Towards Reusable Charts (https://bost.ocks.org/mike/chart/) as the source of the foundational principles.

Using the ProD3 pattern (Pro D3.js Use D3.js to Create Maintainable, Modular, and Testable Charts by Marcos Iglesias https://www.apress.com/gp/book/9781484252024) as the basis for charts pattern.