This example shows a pie chart of browser usage statistics for January 2017, where each slice is colored and labeled by browser name. The chart is built using React and D3.js v4, with the `d3.pie()` layout computing arc angles from the `d_Sigma_X` field of the provided `spots.csv` data. The SVG is rendered via `d3.arc()` paths for the slices and labels, with the chart centered in the viewport. A legend-like title is added as a text element.