Graphviz opens every drawing with a <g class="graph">, numbered
graph0 (one per page of a paginated drawing), and puts each node, edge
and cluster in a group of its own class directly inside it -- a shape no
charting library writes. The group carries a <title> only when the graph
has a name, so the id is what is checked.
Whether an SVG is a Graphviz drawing.
Graphviz opens every drawing with a
<g class="graph">, numberedgraph0(one per page of a paginated drawing), and puts each node, edge and cluster in a group of its own class directly inside it -- a shape no charting library writes. The group carries a<title>only when the graph has a name, so the id is what is checked.