如何迭代<String，Any>类型的MultiValueMap，其中<Any>可以是另一个MultiValueMap，等等

import org.springframework.util.MultiValueMap;

public class MultiValueMapIterator {

    public static void iterateMultiValueMap(MultiValueMap<String, ?> map) {
        for (String key : map.keySet()) {
            System.out.println("Key: " + key);
            System.out.println("Value: " + map.get(key));

            if (map.get(key) instanceof MultiValueMap) {
                iterateMultiValueMap((MultiValueMap<String, ?>) map.get(key));
            }
        }
    }

    public static void main(String[] args) {
        MultiValueMap<String, Object> map = new LinkedMultiValueMap<>();
        map.add("key1", "value1");
        map.add("key2", "value2");

        MultiValueMap<String, Object> nestedMap = new LinkedMultiValueMap<>();
        nestedMap.add("nestedKey", "nestedValue");
        map.add("key3", nestedMap);

        iterateMultiValueMap(map);
    }
}