API-method可以返回不同的类型，如何定义返回类型？

from typing import Union

def get_user_info(user_id: int) -> Union[dict, None]:
    # 模拟获取用户信息
    if user_id == 1:
        return {"name": "Alice", "age": 30}
    else:
        return None

import java.util.Optional;

public class UserService {
    public Optional<User> getUserInfo(int userId) {
        // 模拟获取用户信息
        if (userId == 1) {
            return Optional.of(new User("Alice", 30));
        } else {
            return Optional.empty();
        }
    }
}

class User {
    private String name;
    private int age;

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

    // Getters and setters
}

interface User {
    name: string;
    age: number;
}

function getUserInfo(userId: number): User | null {
    // 模拟获取用户信息
    if (userId == 1) {
        return { name: "Alice", age: 30 };
    } else {
        return null;
    }
}

public enum UserStatus
{
    Active,
    Inactive,
    Suspended
}

public class UserService
{
    public UserStatus GetUserStatus(int userId)
    {
        // 模拟获取用户状态
        if (userId == 1)
        {
            return UserStatus.Active;
        }
        else if (userId == 2)
        {
            return UserStatus.Inactive;
        }
        else
        {
            return UserStatus.Suspended;
        }
    }
}