| This tests that custom properties on element.dataset persist GC. | |
| On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". | |
| PASS d.getAttribute('data-custom-property') is '1' | |
| PASS d.dataset.customProperty is '1' | |
| PASS d.dataset.customProperty is '1' | |
| PASS successfullyParsed is true | |
| TEST COMPLETE | |