public static Future<Optional<String>> checkForUpdate(
      ExecutorService executorService,
      String versionUrl,
      String toolName,
      String toolVersion,
      Consumer<LogEvent> log) {
    return executorService.submit(
        () ->
            performUpdateCheck(
                GlobalConfig.getConfigDir(), toolVersion, versionUrl, toolName, log));
  }
Begins checking for an update in a separate thread.

@param executorService the {@link ExecutorService}
@param versionUrl the location to check for the latest version
@param toolName the tool name
@param toolVersion the tool version
@param log {@link Consumer} used to log messages
@return a new {@link UpdateChecker}
jib-plugins-common/src/main/java/com/google/cloud/tools/jib/plugins/common/UpdateChecker.java