This example shows a hierarchical tree graph of electric vehicle stock values across countries in 2024, with branches for China, India, the United Kingdom, and the USA, each dividing into buses and cars with leaf nodes for BEV and PHEV counts. Using d3.hierarchy and d3.tree, the visualization renders an SVG with curved cubic Bézier paths for links, whose colors derive from node data. Nodes are positioned via the tree layout, with colors indicating country, category, or vehicle type.