@SuppressWarnings("deprecation")  // https://github.com/embulk/embulk/issues/1304
    private static org.embulk.config.ModelManager createModelManager() {
        return new org.embulk.config.ModelManager();
    }
Sets an alternative {@code BulkLoader} instance mainly for testing-purpose.
embulk-core/src/main/java/org/embulk/EmbulkEmbed.java