ed');
    nd.removeChild(b);
    flush();
    assert.equal(nd.children.length, 1, 'children length not decremented due to element removal');
    nd.appendChild(b);
    flush();
    assert.equal(nd.children.length, 2, 'children length not incremented due to element addition');
    var d = document.createElement('div');
    d.innerHTML = 'added';
    nd.insertBefore(d, b);
    flush();
    assert.equal(nd.children.length, 3, 'children length not incremented due to element addition');
    nd.removeChild(d);
  