This example presents a pie chart that visualizes the distribution of total shipping weight by shipping method. The chart is rendered using scalable vector graphics and includes an interactive tooltip that appears on hover, displaying the method and its aggregated weight. The data is loaded from a CSV file and aggregated using `d3.nest()` and `d3.sum()`. The visualization uses `d3.layout.pie()` for the pie layout, `d3.svg.arc()` for the slices, and `d3.scale.category10()` for coloring. A legend is generated from the aggregated data, and all elements are drawn within an SVG container.