@SuppressWarnings("deprecation") // https://github.com/embulk/embulk/issues/1301
    public ResumeStateAction resumeState(final ConfigSource config, final ConfigSource resumeStateConfig) {
        logger.info("Started Embulk v" + EmbulkVersion.VERSION);

        final ResumeState resumeState = resumeStateConfig.loadConfig(ResumeState.class);
        return new ResumeStateAction(config, resumeState);
    }
Sets an alternative {@code BulkLoader} instance mainly for testing-purpose.
embulk-core/src/main/java/org/embulk/EmbulkEmbed.java