I've never used GraphViz, since the example you link to is named 'clusters', the GraphViz documentation has examples for 'clusters':

"Nodes can be clustered together with the "cluster" attribute, which is drawn by having a labelled rectangle around all the nodes in a cluster. An empty string means not clustered...."

In reply to Re: Module GraphViz : make subgraphs ? by marto
in thread Module GraphViz : make subgraphs ? by odrevet

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