This example demonstrates a live-coded workflow for inspecting and cleaning data from the Dutch government’s open-data API for road traffic information, accessed via the `fetch` API. It fetches JSON from the RDW endpoint, extracts values from a specified column (`areaid`), and then logs unique values and filters entries containing “WEST” using standard JavaScript array methods. The code shows a step-by-step refactoring process, with console output at each stage, but does not render a visualization. It uses no external libraries, relying solely on native JavaScript functions like `Set` for deduplication.