code: private void callNextForInternalReasons() throws CloudSpannerSQLException {
      if (!nextCalledForInternalReasons) {
        try {
          nextCalledForInternalReasonsResult = resultSet.next();
        } catch (SpannerException e) {
          throw new CloudSpannerSQLException(e);
        }
        nextCalledForInternalReasons = true;
      }
    }
docs: Advances the underlying {@link com.google.cloud.spanner.ResultSet} to the first position. This
  forces the query to be executed, and ensures that any invalid queries are reported as quickly
  as possible.
  
  @throws CloudSpannerSQLException