federation_graph.ts's graph()
Optionaloptions: any
resolve(node) (which may add an href and override a
label), links, id (a prefix for every generated id) and label (the
document's accessible title)
the SVG, its width and height, and the laid-out nodes and edges
Lays out and draws a federation graph as SVG.
It cannot throw: a failure comes back as a picture saying it could not be drawn.