def _getUniquePrefix(self):
        while 1:
            self._indx += 1
            prefix = 'ns%d' %self._indx
            try:
                self._dom.findNamespaceURI(prefix, self._getNode())
            except DOMException, ex:
                break
        return prefix
I guess we need to resolve all potential prefixes
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/api/SOAPpy/wstools/Utility.py/ElementProxy._getUniquePrefix