This example presents a tree of hierarchical data from the `flare-2.json` dataset, organized with nodes and child edges. Superimposed on the branches are additional curved links connecting various nodes, drawn with a custom `crossDiagonal` function that shifts curves to avoid overlapping the primary D3 `d3.svg.diagonal` edges. A "Regenerate data" button rebuilds the tree and cross-link structure using `d3.shuffle` on a node array, with transitions animating node positions and link paths. The visualization uses D3 v3, rendering nodes as circles and edges as SVG paths with distinct colors for incoming and outgoing cross-links.