code: def merge(self, other):
          
          if not getattr(other, '_catalog', None):
              return  # NullTranslations() has no _catalog
          if self._catalog is None:
              # Take plural and _info from first catalog found
              self.plural = other.plural
              self._info = other._info.copy()
              self._catalog = other._catalog.copy()
          else:
              self._catalog.update(other._catalog)
docs: Merge another translation into this catalog.