This example demonstrates a grid of two SVG rectangles, each 50 by 50 pixels, with a black stroke and no fill, rendered in a 500 by 500 SVG container. It shows how to use a Tile builder pattern with a Tile class to programmatically create SVG `<rect>` elements via the DOM API `document.createElementNS`. The script also directly manipulates the second rectangle’s fill to black, and includes a button labeled “double,” though no click handler is defined. The rendering approach is pure SVG with no external libraries.