def _extract_aliases(self, page, id=None):
        dict_of_keylists = {
            'url' : ['url']
        }

        aliases_dict = provider._extract_from_xml(page, dict_of_keylists)

        try:
            doi = provider.doi_from_url_string(aliases_dict["url"])
            if doi:
                aliases_dict["doi"] = doi
        except __HOLE__:
            pass

        if aliases_dict:
            aliases_list = [(namespace, nid) for (namespace, nid) in aliases_dict.iteritems()]
        else:
            aliases_list = []
        return aliases_list
dataset/ETHPy150Open Impactstory/total-impact-core/totalimpact/providers/dataone.py/Dataone._extract_aliases