Java map转scala map

public static void main(String[] args) {
    Map<String, String> map = new HashMap<String,String>(){
 
 {put("1","2");}};
    scala.collection.mutable.Map<String, String> mapTest = JavaConverters.mapAsScalaMapConverter(map).asScala();
    Object objTest = Map$.MODULE$.<String,String>newBuilder().$plus$plus$eq(mapTest.toSeq());
    Object resultTest = ((scala.collection.mutable.Builder) objTest).result();
    scala.collection.immutable.Map<String,String> resultTest2 = (scala.collection.immutable.Map)resultTest;
    System.out.println(resultTest2.keySet());

}