Tests that the parameters to MediaList.item() / deleteMedium() / appendMedium() are mandatory. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS mediaList.__proto__ is MediaList.prototype PASS mediaList.item() threw exception TypeError: Not enough arguments. PASS mediaList.deleteMedium() threw exception TypeError: Not enough arguments. PASS mediaList.appendMedium() threw exception TypeError: Not enough arguments. PASS successfullyParsed is true TEST COMPLETE