为什么我的网格显示实体字段- Vaadin 14

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() {
        Grid<MyEntity> grid = new Grid<>(MyEntity.class);
        List<MyEntity> entities = new ArrayList<>();
        entities.add(new MyEntity("Alice", 30));
        entities.add(new MyEntity("Bob", 25));
        grid.setItems(entities);

        add(grid);
    }
}

class MyEntity {
    private String name;
    private int age;

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}