如何编写为ListenableFuture添加回调的单元测试用例

import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListeningExecutorService;
import com.google.common.util.concurrent.MoreExecutors;
import org.junit.Before;
import org.junit.Test;

import java.util.concurrent.Callable;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import static org.junit.Assert.assertEquals;

public class ListenableFutureTest {
    private ListeningExecutorService executorService;

    @Before
    public void setUp() {
        executorService = MoreExecutors.listeningDecorator(Executors.newFixedThreadPool(5));
    }
}

@Test
public void testListenableFutureWithCallback() throws Exception {
    // 创建一个Callable任务
    Callable<String> task = () -> {
        TimeUnit.SECONDS.sleep(1);
        return "Hello, World!";
    };

    // 提交任务并获取ListenableFuture对象
    ListenableFuture<String> future = executorService.submit(task);

    // 添加回调函数
    future.addListener(() -> {
        try {
            String result = future.get();
            assertEquals("Hello, World!", result);
            System.out.println("Callback executed successfully. Result: " + result);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }, executorService);

    // 等待回调执行完成
    TimeUnit.SECONDS.sleep(2);
}