t_equals(parent.children[0], child)},
    "Parent's constructor, Parent should have correct child");

// Test that updates are made to previous and new parent when using append().
var newParent = new AnimationGroup();
newParent.append(child);
test(function() {assert_equals(child.parent, newParent)},
    "With .append, child's parent should be updated to new parent");
test(function() {assert_equals(parent.children.length, 0)},
    "With .append, Previous parent should no longer have children");
test(function