progress = {
replay;
const width = 360;
const height = 20;
const context = DOM.context2d(width, height);
context.canvas.style.border = "solid 1px black";
for (let i = width; i >= 0; --i) {
context.clearRect(0, 0, width, height);
context.fillRect(0, 0, i, height);
yield context.canvas;
}
}