This test checks that a SECURITY_ERR exception is raised if an attempt is made to change document.domain to an invalid value. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS document.domain = "apple.com" threw exception SecurityError: Failed to set the 'domain' property on 'Document': 'apple.com' is not a suffix of ''.. PASS successfullyParsed is true TEST COMPLETE