docs: private static void usage(final ArgP argp, final String errmsg,
                              final int retval) {
      System.err.println(errmsg);
      System.err.println("Usage: fsck"
          + " [flags] [START-DATE [END-DATE] query [queries...]] \n"
          + "Scans the OpenTSDB data table for errors. Use the --full-scan flag\n"
          + "to scan the entire data table or specify a command line query to "
          + "scan a subset.\n"
          + "To see the format in which queries should be written, see the help"
          + " of the 'query' command.\n"
          + "The --fix or --fix-all flags will attempt to fix errors,"
          + " but be careful when using them.\n");
      System.err.print(argp.usage());
      System.exit(retval);
    }