code: def _createGaVariant(self):
          
          ret = protocol.Variant()
          if self._creationTime:
              ret.created = self._creationTime
          if self._updatedTime:
              ret.updated = self._updatedTime
          ret.variant_set_id = self.getId()
          return ret
docs: Convenience method to set the common fields in a GA Variant
          object from this variant set.