code: public void delete(List<?> entities) {
      try {
        entityManager.executeEntityListeners(CallbackType.PRE_DELETE, entities);
        Key[] nativeKeys = new Key[entities.size()];
        for (int i = 0; i < entities.size(); i++) {
          nativeKeys[i] = Marshaller.marshalKey(entityManager, entities.get(i));
        }
        nativeWriter.delete(nativeKeys);
        entityManager.executeEntityListeners(CallbackType.POST_DELETE, entities);
      } catch (DatastoreException exp) {
        throw DatastoreUtils.wrap(exp);
      }
    }
docs: Deletes the given entities from the Cloud Datastore.
  
  @param entities
  the entities to delete. The entities must have it ID set for the deletion to succeed.
  @throws EntityManagerException
  if any error occurs while deleting.