code: public static void main(String[] args) {
          System.out.println("Hello World!");
          /*Executor exec = Executors.newCachedThreadPool();
          for(int i = 0; i < 20; i++) {
              final int v = i;
              exec.execute(new Runnable() {
                  @Override
                  public void run() {
                      System.out.println(v);
                  }
              });
          }*/
  
  
          LongStream.rangeClosed(0, 5).map(n -> n * n).forEach(s -> System.out.print(s + " "));
  
      }
docs: non instantiable