{
const context = DOM.context2d(width, height);
while (true) {
mutable frameCount = frameCount + 1;
mutable frameCountPostInc++;
const x =
((Math.sin(Date.now() / 1000) + 1) / 2) * (width - 2 * radius) + radius;
context.clearRect(0, 0, width, height);
context.beginPath();
context.arc(x, height / 2, radius, 0, 2 * Math.PI);
context.fill();
yield context.canvas;
}
}