code: @Deployment public void testIdGeneratorDataSource(){
    List<Thread> threads=new ArrayList<Thread>();
    for (int i=0; i < 20; i++) {
      Thread thread=new Thread(){
        public void run(){
          for (int j=0; j < 5; j++) {
            runtimeService.startProcessInstanceByKey("idGeneratorDataSource");
          }
        }
      }
  ;
      thread.start();
      threads.add(thread);
    }
    for (  Thread thread : threads) {
      try {
        thread.join();
      }
   catch (    InterruptedException e) {
        e.printStackTrace();
      }
    }
  }
  