public static <K, V> Map<K, V> merge(Map<K, V> map1, Map<K, V> map2) {
        Map<K, V> result = newMapWithExpectedSize(map1.size() + map2.size());
        result.putAll(map1);
        result.putAll(map2);
        return result;
    }
Note that the method only checks the immutable classes used by Turms.
turms-server-common/src/main/java/im/turms/server/common/infra/collection/CollectionUtil.java