Simple ForkJoin program on Java

ForkJoinTest.java

import java.util.concurrent.RecursiveTask;
import java.util.concurrent.ForkJoinPool;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;

public interface Node {
    Collection<Node> getChildren();
    
    long getValue();
}

public class Test {
  public void test() {
    int i = 0;
  }
  public static void main(String[] args) {
    Node root = getRootNode();
    new ForkJoinPool().invoke(new ValueSumCounter(root));
  }
}

class ValueSumCounter extends RecursiveTask<Long>{
    private final Node node;
    
    public ValueSumCounter(Node node) {
        this.node = node;
    }

    @Override
    protected Long compute() {
        long sum = node.getValue();
        List<ValueSumCounter> subTasks = new LinkedList<>();
        
        for(Node child : node.getChildren()) {
            ValueSumCounter task = new ValueSumCounter(child);
            task.fork();
            subTasks.add(task);
        }
        
        for(ValueSumCounter task : subTasks) {
            sum += task.join();
        }
        
        return sum;
    }
    
}