Java Collection - 如何测试列表是否是不可修改的列表

import java.util.Collections;
import java.util.LinkedList;
import java.util.List;

public class Main {
  public static void main(String[] args) {
    List<Integer> list = new LinkedList<Integer>();
    list.add(1);
    List<Integer> unmodifiableList = Collections.unmodifiableList(list);
    System.out.println(unmodifiableList.getClass());
    if (unmodifiableList.getClass().getName().contains("UnmodifiableList"))
      System.out.println(true);
  }
}