code: func dotLegend(rpt *Report, g graph, origCount, droppedNodes, droppedEdges int) string {
  	label := legendLabels(rpt)
  	label = append(label, legendDetailLabels(rpt, g, origCount, droppedNodes, droppedEdges)...)
  	return fmt.Sprintf(`subgraph cluster_L { L [shape=box fontsize=32 label="%s\l"] }`, strings.Join(label, `\l`))
  }
docs: // dotLegend generates the overall graph label for a report in DOT format.