{
const w = width;
const h = 600;
const ctx = DOM.context2d(w, h);
ctx.lineJoin = "round";
ctx.lineCap = "round";
ctx.lineWidth = 0.5
const projection = d3.geoMercator()
.fitSize([w, h], boston_neighborhoods);
const path = d3.geoPath(projection, ctx);
for(let feature of boston_neighborhoods.features) {
ctx.beginPath();
path(feature);
ctx.stroke();
}
return ctx.canvas;
}