This example visualizes world atlas country polygons, highlighting those with missing identifiers in red and valid ones in green. It uses d3.geoPath with a d3.geoNaturalEarth1 projection to render the map, and the topojson library’s feature function to convert TopoJSON data from the world-atlas package into GeoJSON features. The visualization supports zooming via d3.zoom, and a color legend is included. The code also appends hover titles showing each country’s ID.