code: def get_object_cache_keys(instance):
      
      if instance.pk is None or instance._state.adding:
          return []
  
      keys = []
      tr_models = instance._parler_meta.get_all_models()
  
      # TODO: performs a query to fetch the language codes. Store that in memcached too.
      for language in instance.get_available_languages():
          for tr_model in tr_models:
              keys.append(get_translation_cache_key(tr_model, instance.pk, language))
  
      return keys
docs: Return the cache keys associated with an object.