ssert_equals(rect1.width.animVal.value, 150);
    assert_equals(rect1.width.baseVal.value, 150);

    assert_equals(rect2.width.animVal.value, 50);
    assert_equals(rect2.width.baseVal.value, 150);
}

smil_async_test((t) => {
    var rects = rootSVGElement.ownerDocument.getElementsByTagName("rect");
    rect1 = rects[0];
    rect2 = rects[1];

    const expectedValues = [
        // [animationId, time, sampleCallback]
        ["an1", 0.0,   sample1],
        ["an1", 2.0,   sample2],
        ["an1", 2.001, 