This example reproduces Sol LeWitt’s geometric wall drawings using D3 v7. It displays a grid of black horizontal and vertical bars, both rendered as SVG rectangles. Two SVG masks, each containing a large star-shaped symbol from `d3.symbol`, selectively reveal or hide the bars in opposite patterns. The masks are created with `svg.call(renderMask, ...)`, using inverted fill colors to alternate which parts of the grid appear.