救救小白，LC49题字母异位词分组

这个该怎么改才能输出呀

import java.util.Map;
import java.util.HashMap;
public class demoMedium49 {

    public static void main(String[] args) {
        String[] array = new String[] {"tea" ,"eat" ,"tan" };
        System.out.println(groupAnagrams(array));

    }
    


    public static List<List<String>> groupAnagrams(String[] strs) {
        Map<String, List<String>> map = new HashMap<String, List<String>>();
        for (String str : strs) {
            int[] counts = new int[26];
            int length = str.length();
            for (int i = 0; i < length; i++) {
                counts[str.charAt(i) - 'a']++;
            }
            StringBuffer sb = new StringBuffer();
            for (int i = 0; i < 26; i++) {
                if (counts[i] != 0) {
                    sb.append((char) ('a' + i));
                    sb.append(counts[i]);
                }
            }
            String key = sb.toString();
            List<String> list = map.getOrDefault(key, new ArrayList<String>());
            list.add(str);
            map.put(key, list);
        }
        return new ArrayList<List<String>>(map.values());
    
    }
    
}

package com.example.demo.test;

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

/**
 * 
 * @作者:Roc-xb
 * @联系QQ:327844761
 * @微信公众号：ewbang
 *
 */
public class Test01 {
	public static void main(String[] args) {
		String[] array = { "eat", "tea", "tan", "ate", "nat", "bat" };
		System.out.println(groupAnagrams(array));

	}

	public static List<List<String>> groupAnagrams(String[] strs) {
		Map<String, List<String>> map = new HashMap<String, List<String>>();
		for (String str : strs) {
			char[] array = str.toCharArray();
			Arrays.sort(array);
			String key = new String(array);
			List<String> list = map.getOrDefault(key, new ArrayList<String>());
			list.add(str);
			map.put(key, list);
		}
		return new ArrayList<List<String>>(map.values());
	}

}