Missing asMap-implementation (for Java)

Example.java

public class Example {
    public void example() {
        Map<String, String> map = MapUtil.asMap("key", "value").entry("key2", "value2");
    }
}

MapUtils.java

public class MapUtils {
    public static <K, V> MapBuilder<K, V> asMap(K key, V value) {
        return new MapBuilder<K, V>().entry(key, value);
    }

    public static class MapBuilder<K, V> extends HashMap<K, V> {
        public MapBuilder<K, V> entry(K key, V value) {
            this.put(key, value);
            return this;
        }
    }
}