This example shows a pie chart of monthly sales totals, with each slice labeled by its month name directly on the chart. It loads CSV data from a GitHub Gist, aggregates the raw records by month using `d3.rollup` and `d3.sum`, then draws the chart with `d3.pie()` and `d3.arc()`. The SVG rendering uses `d3.scaleOrdinal` with `d3.schemeCategory10` for slice colors and places text labels at arc centroids.