This example displays a choropleth map of Australian electoral regions, colored by electoral division using a categorical color scale. The map renders as SVG paths generated with `d3.geoPath` and a `geoMercator` projection, with state names positioned at path centroids. The code loads TopoJSON data from `australia.json`, extracts features via `topojson.feature`, and applies `d3.scaleOrdinal` with `schemeCategory10` for fills.