java忽略强制转换泛型类型的警告

import java.util.List;
// SuppressWarnings在java.lang包下

@SuppressWarnings("unchecked")
List<String> list = (List<String>) obj;

@SuppressWarnings("unchecked")
public void test(Map<String, Object> map) {
    List<String> list = (List<String>) map.get("list");
    System.out.println(list);
}