This test ensures that we can attach various DOMs to the document.
On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
PASS u.tagName is 'Long'
PASS (new XMLSerializer()).serializeToString(doc) is ''
PASS u.tagName is 'Long'
PASS (new XMLSerializer()).serializeToString(doc) is '15'
PASS u.tagName is 'Long'
PASS (new XMLSerializer()).serializeToString(doc) is '1'
PASS u.tagName is 'Long'
PASS (new XMLSerializer()).serializeToString(doc) is '15116'
PASS successfullyParsed is true
TEST COMPLETE