如何在Vaadin 21网格中预选项目？所选内容不显示在UI中

import com.vaadin.flow.component.grid.Grid;
import com.vaadin.flow.component.orderedlayout.VerticalLayout;
import com.vaadin.flow.router.Route;

import java.util.ArrayList;
import java.util.List;

@Route("")
public class MainView extends VerticalLayout {

    public MainView() {
        // 创建数据模型
        List<Person> persons = new ArrayList<>();
        persons.add(new Person("John Doe", 30));
        persons.add(new Person("Jane Doe", 25));

        // 创建网格并设置数据源
        Grid<Person> grid = new Grid<>(Person.class);
        grid.setItems(persons);

        // 设置选择模式
        grid.setSelectionMode(Grid.SelectionMode.MULTI);

        // 预选第一个项目
        grid.asSingleSelect().select(persons.get(0));

        // 或者预选多个项目
        // grid.asMultiSelect().select(persons.get(0), persons.get(1));

        // 将网格添加到布局中
        add(grid);
    }

    public static class Person {
        private String name;
        private int age;

        public Person(String name, int age) {
            this.name = name;
            this.age = age;
        }

        public String getName() {
            return name;
        }

        public int getAge() {
            return age;
        }
    }
}