docs: def get_current_key(self, resource_name):
          """
          Returns a restclients.Key object for the given resource.  If the
          resource isn't found, or if there is an error communicating with the
          KWS, a DataFailureException will be thrown.
          """
          url = ENCRYPTION_CURRENT_KEY_URL.format(resource_name)
          return self._key_from_json(self._get_resource(url))