def _get_container(self, thread_id, document_html, container, index):
        if not document_html:
            document_html = self.get_thread(thread_id).get("html")
            if not document_html:
                return None
        tree = self.parse_document_html(document_html)
        lists = list(tree.iter(container))
        if not lists:
            return None
        try:
            return lists[index]
        except __HOLE__:
            return None
dataset/ETHPy150Open quip/quip-api/python/quip.py/QuipClient._get_container