This example visualizes the total capacity of Dutch parking areas by combining two RDW open datasets, one containing area manager info and another with vehicle specifications. Using a custom asynchronous `getDatasets()` function with `await fetch`, it merges records by matching `areamanagerid`, sums the `capacity` fields, and filters out zero-capacity entries. The resulting combined data is logged to the console, demonstrating data joining and reduction with JavaScript array methods, though no actual SVG bar chart rendering is implemented despite the title.