code: public static void main(String[] args) throws Exception {
          LoggerContext context = (LoggerContext) LoggerFactory.getILoggerFactory();
          context.getLoggerList().get(0).setLevel(Level.ERROR);
  
          System.out.println("Pravega Admin Tools.\n");
          @Cleanup
          AdminCommandState state = new AdminCommandState();
  
          // Output loaded config.
          System.out.println("Initial configuration:");
          val initialConfigCmd = new ConfigListCommand(new CommandArgs(Collections.emptyList(), state));
          initialConfigCmd.execute();
  
          // Continuously accept new commands as long as the user entered one.
          System.out.println(String.format("%nType \"%s\" for list of commands, or \"%s\" to exit.", CMD_HELP, CMD_EXIT));
          @Cleanup
          Scanner input = new Scanner(System.in);
          while (true) {
              System.out.print(System.lineSeparator() + "> ");
              String line = input.nextLine();
              if (Strings.isNullOrEmpty(line.trim())) {
                  continue;
              }
  
              Parser.Command pc = Parser.parse(line);
              switch (pc.getComponent()) {
                  case CMD_HELP:
                      printHelp(null);
                      break;
                  case CMD_EXIT:
                      System.exit(0);
                      break;
                  default:
                      execCommand(pc, state);
                      break;
              }
          }
      }
docs: Main entry point for the Admin Tools Runner.
  <p>
  To speed up setup, create a config.properties file and put the following properties (at a minimum):
  <p>
  pravegaservice.containerCount={number of containers}
  pravegaservice.zkURL={host:port for ZooKeeper}
  bookkeeper.bkLedgerPath={path in ZooKeeper where BookKeeper stores Ledger metadata}
  bookkeeper.zkMetadataPath={path in ZooKeeper where Pravega stores BookKeeperLog metadata}
  <p>
  Then invoke this program with:
  -Dpravega.configurationFile=config.properties
  
  @param args Arguments.
  @throws Exception If one occurred.