Java:返回嵌套列表的类型

import java.util.List;

public class NestedList<T> {
    private List<List<T>> nestedList;

    public List<List<T>> getNestedList() {
        return nestedList;
    }

    public void setNestedList(List<List<T>> nestedList) {
        this.nestedList = nestedList;
    }
}

import java.util.Arrays;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        List<List<Integer>> nestedList = Arrays.asList(
                Arrays.asList(1, 2, 3),
                Arrays.asList(4, 5, 6),
                Arrays.asList(7, 8, 9)
        );

        NestedList<Integer> wrapper = new NestedList<>();
        wrapper.setNestedList(nestedList);

        List<List<Integer>> result = wrapper.getNestedList();
        System.out.println(result);
    }
}