This example shows a map of Boston neighborhoods rendered as gray SVG paths on a 700 by 580 canvas. It uses D3 v4’s `d3.geoAlbers` projection and `d3.geoPath` to convert GeoJSON features from an embedded `mapdata.js` file into visible shapes. The code binds the neighborhood polygons to `path` elements and applies a uniform fill color, demonstrating a basic choropleth-style layout without additional styling or interactivity.