This example reproduces a Sol LeWitt art piece using D3 v6 with SVG rendering. It draws 100 horizontal and 100 vertical rectangles that are partially hidden by two circular masks, creating a geometric grid pattern with a circular cutout effect. The code uses `d3.select`, `d3.range`, and the `.join()` pattern to generate the rectangles, while masks are constructed with SVG `mask` elements. The visualization fills the entire browser window and is rendered entirely through SVG attributes.