Testing
This visualization presents annual U.S. influenza-like illness (ILI) totals as multi-line curves, with each year (2015–2019) shown as a separate line over weeks of the year. The chart aggregates the CDC ILINet dataset by year, region, and week using the vega-lite-api, which wraps Vega-Lite and Vega for declarative rendering. Each line uses an unordered color scale for the year field, making it harder to discern chronological trends. The code imports data via `d3.csv` and configures axis styling through a custom Vega-Lite config object.