import org.elasticsearch.transport.ReceiveTimeoutTransportException; //导入依赖的package包/类
/**
 * Test waiting for a task that times out.
 * @param wait wait for the running task and return all the failures you accumulated waiting for it
 */
private void waitForTimeoutTestCase(Function<TaskId, ? extends Iterable<? extends Throwable>> wait) throws Exception {
    // Start blocking test task
    ListenableActionFuture<TestTaskPlugin.NodesResponse> future = TestTaskPlugin.TestTaskAction.INSTANCE.newRequestBuilder(client())
            .execute();
    try {
        TaskId taskId = waitForTestTaskStartOnAllNodes();

        // Wait for the task to start
        assertBusy(() -> client().admin().cluster().prepareGetTask(taskId).get());

        // Spin up a request that should wait for those tasks to finish
        // It will timeout because we haven't unblocked the tasks
        Iterable<? extends Throwable> failures = wait.apply(taskId);

        for (Throwable failure : failures) {
            assertNotNull(
                    ExceptionsHelper.unwrap(failure, ElasticsearchTimeoutException.class, ReceiveTimeoutTransportException.class));
        }
    } finally {
        // Now we can unblock those requests
        TestTaskPlugin.UnblockTestTasksAction.INSTANCE.newRequestBuilder(client()).get();
    }
    future.get();
}