This test checks to see if document.head is available, readonly, and the same element as what we would expect by getting it by other means.

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".

PASS document.head is document.getElementsByTagName('head')[0]
PASS document.head !== 1 is true
PASS document.head is null
PASS successfullyParsed is true

TEST COMPLETE