code: public static void main(String[] args) throws Exception {
      Configuration conf = HBaseConfiguration.create();
      String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
      if (otherArgs.length < 2) {
        usage("Wrong number of arguments: " + otherArgs.length);
        System.exit(-1);
      }
      if (conf.get(BigtableOptionsFactory.PROJECT_ID_KEY) == null) {
        usage("Must specify the property " + BigtableOptionsFactory.PROJECT_ID_KEY);
        System.exit(-1);
      }
      if (conf.get(BigtableOptionsFactory.INSTANCE_ID_KEY) == null) {
        usage("Must specify the property" + BigtableOptionsFactory.INSTANCE_ID_KEY);
        System.exit(-1);
      }
  
      Job job = createSubmittableJob(conf, otherArgs);
      System.exit(job.waitForCompletion(true)? 0 : 1);
    }
docs: Main entry point.
  
  @param args  The command line parameters.
  @throws java.lang.Exception When running the job fails.