chart = {
const svg = d3.create("svg")
.attr("viewBox", [0, 0, 975, 610]);
svg.append("g")
.attr("transform", "translate(610,20)")
.append(() => legend({color, title: data.title, width: 260, tickFormat: ".0s"}));
svg.append("g")
.selectAll("path")
.data(topojson.feature(us, us.objects.counties).features)
.join("path")
.attr("fill", d => color(data.get(d.id)))
.attr("stroke", "white")
.attr("d", path)
svg.append("path")
.datum(topojson.mesh(us, us.objects.states, (a, b) => a !== b))
.attr("fill", "none")
.attr("stroke", "grey")
.attr("stroke-linejoin", "round")
.attr("d", path);
return svg.node();
}