code: static DatastoreException throwInvalidRequest(String massage, Object... params) {
      throw new DatastoreException(
          UNKNOWN_CODE, String.format(massage, params), "FAILED_PRECONDITION");
    }
docs: Throw a DatastoreException with {@code FAILED_PRECONDITION} reason and the {@code message} in a
  nested exception.
  
  @throws DatastoreException every time