PASS dialog.returnValue is ''
PASS dialog.returnValue is 'null'
PASS dialog.returnValue is 'Should not change because no argument to close()'
+PASS dialog.returnValue is 'Should not change because of undefined argument to close()'
PASS dialog.close('blah') threw exception InvalidStateError: Failed to execute 'close' on 'HTMLDialogElement': The element does not have an 'open' attribute, and therefore cannot be closed..
PASS dialog.returnValue is 'Should not change because close() is invalid'
PASS successfullyParsed is true