def _parse_itemIdentifiers(self, verbElement):
        """
        Parse item identifiers out of items and retract requests.
        """
        self.itemIdentifiers = []
        for element in verbElement.elements():
            if element.uri == NS_PUBSUB and element.name == 'item':
                try:
                    self.itemIdentifiers.append(element["id"])
                except __HOLE__:
                    raise BadRequest()
dataset/ETHPy150Open ralphm/wokkel/wokkel/pubsub.py/PubSubRequest._parse_itemIdentifiers