chart = {
const svg = d3.create("svg")
.attr("viewBox", [0, 0, 975, 610]);
svg.append("path")
.datum(topojson.mesh(us, us.objects.states, (a, b) => a !== b))
.attr("fill", "none")
.attr("stroke", "black")
.attr("stroke-width", 1)
.attr("stroke-linejoin", "round")
.attr("d", path);
svg.append("path")
.datum(topojson.feature(us, us.objects.nation))
.attr("fill", "none")
.attr("stroke", "black")
.attr("stroke-width", 1)
.attr("stroke-linejoin", "round")
.attr("d", path);
svg.append("g")
.selectAll("path")
.data(topojson.feature(cbsa, cbsa.objects.cb_2018_us_cbsa_5m).features)
.join("path")
.attr("fill", "none")
.attr("stroke", "black")
.attr("stroke-width", '0.5px')
.attr("d", path)
.append("title")
.text(d => String(d.properties.NAME));
return svg.node();
}