It&#x27;s produced with a tool called Graphviz:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Graphviz" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Graphviz</a><p>The main Graphviz website is down at the time of my posting this comment:<p><a href="http:&#x2F;&#x2F;www.graphviz.org&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.graphviz.org&#x2F;</a>