This visualization demonstrates how to manage timers for blinking effects in interactive data visualizations. It renders a set of colored circles using D3.js, where clicking a circle highlights it and triggers a blinking animation through alternating stroke colors. The code uses D3’s selection API with `select` and `join` for efficient SVG updates, and manages a timer via `setTimeout` within the main function. A cleanup function is returned to clear the timeout, ensuring proper handling during hot reloads, similar to React’s `useEffect` cleanup pattern.