This example animates a bar chart race, showing how categorical rankings change over time as bars reorder and rescale. The chart uses D3’s `d3.create`, `d3.rollup`, `d3.pairs`, and `d3.groups` to process data, with `d3.transition` and `.ease(d3.easeLinear)` driving smooth keyframe animations. The code imports helper functions like `bars`, `axis`, `labels`, and `ticker` from an external module. It renders as an SVG with a viewBox, and the animation runs through an async generator that yields transitions sequentially.