ren.
var parent = new AnimationGroup();
test(function() {assert_equals(parent.children.length, 0)},
    "Parent should have zero children");

// Test that updates are made to child when constructing parent.
var parent = new AnimationGroup([child]);
test(function() {assert_equals(child.parent, parent)},
    "Parent's constructor, Child's parent should be set to parent");
test(function() {assert_equals(parent.children.length, 1)},
    "Parent's constructor, Parent should have 1 child");
test(function() {asser