This example animates cumulative confirmed COVID-19 cases across multiple countries, plotting each country as a colored line over days since its first confirmed case. The animation progressively reveals data up to day 92, with circles and labels marking the latest value of each line. Built with D3 v5, it uses `nest()` to group data by country, `scaleLinear` for axes, `line` with `curveBasis` for smooth paths, and transitions to update paths over time. The data comes from two CSV files processed via `loadAndProcessData`.