static void toSpecific(final String runningVersion, final String targetVersion, final boolean forced) throws IOException {
        logger.info("================================== [ NOTICE ] ==================================");
        logger.info(" Embulk `selfupdate` will not be available at some point in v0.11.*.");
        logger.info(" Be prepared by controlling Embulk versions with your own deployment strategies.");
        logger.info(" See https://github.com/embulk/embulk/issues/1495 for the details.");
        logger.info("================================================================================");

        final Path pathRunning = identifyRunningJarPath();
        update(targetVersion, forced, pathRunning, "Embulk/" + runningVersion);
    }
Runs the selfupdate subcommand of Embulk.

<p>It uses {@link java.net.HttpURLConnection} so that CLI classes do not need additional dependedcies.

<p>TODO: Support HTTP(S) proxy. The original Ruby version did not support as well, though.
embulk-core/src/main/java/org/embulk/cli/SelfUpdate.java