You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: retry-classifier-customization.rs
    path of file: ./repos/aws-sdk-rust/sdk/s3/tests
    
    the code of the file until where you have to start completion: /*
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0
 */

use aws_sdk_s3::config::interceptors::InterceptorContext;
use aws_sdk_s3::config::retry::{ClassifyRetry, RetryAction, RetryConfig};
use aws_sdk_s3::config::SharedAsyncSleep;
use aws_smithy_async::rt::sleep::TokioSleep;
use aws_smithy_runtime::client::http::test_util::{ReplayEvent, StaticReplayClient};
use aws_smithy_runtime_api::client::retries::classifiers::RetryClassifierPriority;
use aws_smithy_types::body::SdkBody;
use std::sync::{Arc, Mutex};

#[derive(Debug, Clone)]
struct CustomizationTestClassifier {
    counter: Arc<Mutex<u8>>,
}

impl CustomizationTestClassifier {
    pub fn new() -> Self {
        Self {
            counter: Arc::new(Mutex::new(0u8)),
        }
    }

    pub fn counter(&self) -> u8 {
        *self.counter.lock().unwrap()
    }
}

impl ClassifyRetry for CustomizationTestClassifier {
    fn classify_retry(&self, ctx: &InterceptorContext) -> RetryAction {
        *self.counter.lock().unwrap() += 1;

        // Interceptors may call this classifier before a response is received. If a response was received,
        // ensure that it has the expected status code.
        if let Some(res) = ctx.response() {
            assert_eq!(
                500,
                res.status().as_u16(),
                "expected a 500 response from test connection"
            );
        }

        RetryAction::RetryForbidden
    }

    fn name(&self) -> &'static str {
        "Custom Retry Classifier"
    }
}

fn req() -> http::Request<SdkBody> {
    http::Request::builder()
        .body(SdkBody::from("request body"))
        .unwrap()
}

fn ok() -> http::Response<SdkBody> {
    http::Response::builder()
        .status(200)
        .body(SdkBody::from("Hello!"))
        .unwrap()
}

fn err() -> http::Response<SdkBody> {
    http::Response::builder()
        .status(500)
        .body(SdkBody::from("This was an error"))
        .unwrap()
}

#[tokio::test]
async fn test_retry_classifier_customization_for_service() {
    let http_client = StaticReplayClient::new(vec![
        ReplayEvent::new(req(), err()),
        ReplayEvent::new(req(), ok()),
    ]);

    let customization_test_classifier = CustomizationTestClassifier::new();

    let config = aws_sdk_s3::Config::builder()
        .with_test_defaults()
        .sleep_impl(SharedAsyncSleep::new(TokioSleep::new()))
        .http_client(http_client)
        .retry_config(RetryConfig::standard())
        .retry_classifier(customization_test_classifier.clone())
        .build();

    let client = aws_sdk_s3::Cl
    
async fn test_retry_classifier_customization_ordering() {
    let http_client = StaticReplayClient::new(vec![
        ReplayEvent::new(req(), err()),
        ReplayEvent::new(req(), ok()),
    ]);

    let classifier_a = OrderingTestClassifier::new("6", RetryClassifierPriority::default());
    let classifier_b = OrderingTestClassifier::new(
        "5",
        RetryClassifierPriority::run_before(classifier_a.priority()),
    );
    let classifier_c = OrderingTestClassifier::new(
        "4",
        RetryClassifierPriority::run_before(classifier_b.priority()),
    );
    let classifier_d = OrderingTestClassifier::new(
        "3",
        RetryClassifierPriority::run_before(classifier_c.priority()),
    );
    let classifier_e = OrderingTestClassifier::new(
        "2",
        RetryClassifierPriority::run_before(classifier_d.priority()),
    );
    let classifier_f = OrderingTestClassifier::new(
        "1",
        RetryClassifierPriority::run_before(classifier_e.priority()),
    );

    let config = aws_sdk_s3::Config::builder()
        .with_test_defaults()
        .sleep_impl(SharedAsyncSleep::new(TokioSleep::new()))
        .http_client(http_client)
        .retry_config(RetryConfig::standard())
        .retry_classifier(classifier_d.clone())
        .retry_classifier(classifier_b.clone())
        .retry_classifier(classifier_f.clone())
        .build();

    let client = aws_sdk_s3::Client::from_conf(config);
    let _ = client
        .get_object()
        .bucket("bucket")
        .key("key")
        .customize()
        .config_override(
            aws_sdk_s3::config::Config::builder()
                .retry_classifier(classifier_c.clone())
                .retry_classifier(classifier_a.clone())
                .retry_classifier(classifier_e.clone()),
        )
        .send()
        .await
        .expect_err("fails without attempting a retry");

    // ensure our classifiers were each called at least once.
    assert_ne!(classifier_a.counter(), 0, "classifier_a was never called");
    assert_ne!(classifier_b.counter(), 0, "classifier_b was never called");
    assert_ne!(classifier_c.counter(), 0, "classifier_c was never called");
    assert_ne!(classifier_d.counter(), 0, "classifier_d was never called");
    assert_ne!(classifier_e.counter(), 0, "classifier_e was never called");
    assert_ne!(classifier_f.counter(), 0, "classifier_f was never called");

    // ensure the classifiers were called in the correct order.
    logs_assert(|lines: &[&str]| {
        let mut found_log_a = false;
        let mut line_iter = lines.iter();

        while found_log_a == false {
            match line_iter.next() {
                Some(&line) => {
                    if line.contains("Running classifier 1") {
                        found_log_a = true;
                    }
                }
                None => {
                    return Err("Couldn't find log line for classifier 1".to_owned());
                }
            }
        }

        for i in 2..=6 {
            match line_iter.next() {
                Some(&line) => {
                    if line.contains(&format!("Running classifier {i}")) {
                        // pass
                    } else {
                        return Err(format!("Expected to find log line for classifier {i} after {} but found '{line}'", i - 1));
                    }
                }
                None => {
                    return Err(format!("Logs ended earlier than expected ({i})"));
                }
            }
        }

        Ok(())
    });
}