Transforming list of elements in Map using java8 streams

Question

Assume that there are below set of ball buckets:

BallBucket1 = Color=RED, BallCount=10

BallBucket2 = Color=RED, BallCount=5

BallBucket3 = Color=GREEN, BallCount=10

Now I want to put these ball in a rack, here I want all ball of RED color in one section of rack and balls of GREEN color in another section of the same rack.

I have written below code which solves my problem but, here I want to create externally map and fill it in pick() operation. I wanted to know if there is any terminal operation which can do the same task for me (something like Collectors.toMap())

package com.test;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

class BallBucket{
    String color;
    int count;
        
    public BallBucket(String color, int count) {
        super();
        this.color = color;
        this.count = count;
    }
    
    public String getColor() {
        return color;
    }
    public void setColor(String color) {
        this.color = color;
    }
    public int getCount() {
        return count;
    }
    public void setCount(int count) {
        this.count = count;
    }
}

public class TestStreams {
    public static void main(String[] args) {
        List<BallBucket> bucket = new ArrayList<BallBucket>();      
        
        bucket.add(new BallBucket("RED", 10));
        bucket.add(new BallBucket("RED", 5));
        bucket.add(new BallBucket("GREEN", 10));
        
        Map<String, Integer> ballRack = new HashMap<String, Integer>();
        
        bucket.stream()
                .peek(ballBucket->{
                    ballRack.compute(ballBucket.color, (key,val)->val==null? ballBucket.count:val+ballBucket.count);
                }).count();
        
        System.out.println(ballRack);
        
    }
}

output: {RED=15, GREEN=10}