This tests verifies that HTMLCollection.namedItem() argument is mandatory On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS htmlCollection.__proto__ is HTMLCollection.prototype PASS htmlCollection.length is 1 PASS htmlCollection.namedItem('testLink') is testLink PASS htmlCollection.namedItem() threw exception TypeError: Failed to execute 'namedItem' on 'HTMLCollection': 1 argument required, but only 0 present.. PASS successfullyParsed is true TEST COMPLETE