5 Step 2: Do another thing
6 Step 3: Do one last thing
7 This tests that if aria-hidden changes on an element, all it's existing children will update their children caches
9 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
12 PASS main.childrenCount is 1
13 PASS main.childrenCount is 2
14 PASS main.childAtIndex(1).childrenCount is 1
15 PASS successfullyParsed is true