Java Stream - 如何映射到值的两倍

import java.util.Arrays;
import java.util.List;

public class Main {
   public static void main(String[] args) {
     List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
     numbers.stream().map(n -> n * n).forEach(System.out::println);
   }

}