code: def delete_translation(self, language_code, related_name=None):
          
          if language_code is None:
              raise ValueError(get_null_language_error())
  
          if related_name is None:
              metas = self._parler_meta
          else:
              metas = [self._parler_meta[related_name]]
  
          num_deleted = 0
          for meta in metas:
              try:
                  translation = self._get_translated_model(language_code, meta=meta)
              except meta.model.DoesNotExist:
                  continue
  
              # By using the regular model delete, the cache is properly cleared
              # (via _delete_cached_translation) and signals are emitted.
              translation.delete()
              num_deleted += 1
  
              # Clear other local caches
              try:
                  del self._translations_cache[meta.model][language_code]
              except KeyError:
                  pass
              try:
                  del self._prefetched_objects_cache[meta.rel_name]
              except (AttributeError, KeyError):
                  pass
  
          if not num_deleted:
              raise ValueError("Translation does not exist: {0}".format(language_code))
  
          return num_deleted
docs: Delete a translation from a model.
  
          :param language_code: The language to remove.
          :param related_name: If given, only the model matching that related_name is removed.