code: public List<Entity> fetchEntitiesWithKeys(String firstKeyName, String secondKeyName) {
      Datastore datastore = transaction.getDatastore();
      // [START fetchEntitiesWithKeys]
      KeyFactory keyFactory = datastore.newKeyFactory().setKind("MyKind");
      Key firstKey = keyFactory.newKey(firstKeyName);
      Key secondKey = keyFactory.newKey(secondKeyName);
      List<Entity> entities = transaction.fetch(firstKey, secondKey);
      for (Entity entity : entities) {
        // do something with the entity
      }
      transaction.commit();
      // [END fetchEntitiesWithKeys]
      return entities;
    }
docs: [VARIABLE "my_second_key_name"]