docs: def _parse_for_errors(self):
          """ Look for an error tag and raise APIError for fatal errors or APIWarning for nonfatal ones. """
          error = self._response.find('{www.clusterpoint.com}error')
          if error is not None:
              if error.find('level').text.lower() in ('rejected', 'failed', 'error', 'fatal'):
                  raise APIError(error)
              else:
                  warnings.warn(APIWarning(error))