code: def validate_unique(self, exclude=None):
          
          # This is called from ModelForm._post_clean() or Model.full_clean()
          errors = {}
          try:
              super(TranslatableModelMixin, self).validate_unique(exclude=exclude)
          except ValidationError as e:
              errors = e.message_dict
  
          for local_cache in six.itervalues(self._translations_cache):
              for translation in six.itervalues(local_cache):
                  if is_missing(translation):  # Skip fallback markers
                      continue
  
                  try:
                      translation.validate_unique(exclude=exclude)
                  except ValidationError as e:
                      errors.update(e.message_dict)
  
          if errors:
              raise ValidationError(errors)
docs: Also validate the unique_together of the translated model.