This example displays a map of the United States, including Alaska, Hawaii, and Puerto Rico, using a custom composite projection defined in `albers-usa-pr.js`. The code builds on `d3.geoAlbers` and `d3.geoConicEqualArea` to create `d3.geoAlbersUsaPr`, which is then used with `d3.geoPath` to render state boundaries from TopoJSON data in `states.js`. SVG paths are generated for each state, filled gray with white strokes.