This example uses small multiples to display the Consumer Price Index (CPI) of four grains—Corn, Rice, Rye, and Wheat—from 2000 to 2015, with each grain in its own line chart. A color legend identifies each grain’s stroke color. The code loads CSV data via `d3.csv`, renders SVG line charts using `d3.line` and `d3.axisBottom`, and builds the legend with `d3.legendColor` from the d3-legend library.