code: public static void main(String[] args) {
      ProgramDriver programDriver = new ProgramDriver();
      int exitCode = -1;
      try {
        programDriver.addClass("export-table", Export.class,
            "A map/reduce program that exports a table to a file.");
        programDriver.addClass("import-table", Import.class,
            "A map/reduce program that imports a table to a file.");
        programDriver.driver(args);
        exitCode = programDriver.run(args);
      } catch (Throwable e) {
        e.printStackTrace();
      }
      System.exit(exitCode);
    }
docs: <p>main.</p>
  
  @param args an array of {@link java.lang.String} objects.