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: startup.rs
    path of file: ./repos/aws-doc-sdk-examples/rustv1/cross_service/rest_ses/tests/api
    
    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_config::BehaviorVersion;
use once_cell::sync::Lazy;
use rest_ses::{
    client::{RdsClien
    
async fn prep_app(config: aws_config::ConfigLoader) -> (String, RdsClient) {
    let environment = Lazy::force(&TRACING);
    let settings = get_settings(environment).expect("failed to read configuration");

    let config = config.load().await;

    let rds = RdsClient::new(&settings.rds, &config);
    let ses = SesClient::new(&settings.ses, &config);
    let listener =
        TcpListener::bind("127.0.0.1:0").expect("Failed to bind to unused port for testing");
    let port = listener.local_addr().unwrap().port();
    let server =
        rest_ses::startup::run(listener, rds.clone(), ses).expect("Failed to initalize server!");
    tokio::spawn(server);
    let address = format!("http://127.0.0.1:{port}");
    (address, rds)
}