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: identity.rs
    path of file: ./repos/aws-sdk-rust/sdk/aws-smithy-runtime-api/src/client
    
    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 crate::box_error::BoxError;
use crate::client::runtime_components::sealed::ValidateConfig;
use crate::client::runtime_components::{RuntimeComponents, RuntimeComponentsBuilder};
use crate::impl_shared_conversions;
use aws_smithy_types::config_bag::ConfigBag;
use std::any::Any;
use std::fmt;
use std::fmt::Debug;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::Arc;
use std::time::SystemTime;

#[cfg(feature = "http-auth")]
pub mod http;

n
    
    fn check_send_sync() {
        fn is_send_sync<T: Send + Sync>(_: T) {}
        is_send_sync(Identity::new("foo", None));
    }

    #[test]
    fn create_retrieve_identity() {
        #[derive(Debug)]
        struct MyIdentityData {
            first: String,
            last: String,
        }

        let ts = SystemTimeSource::new();
        let expiration = ts.now();
        let identity = Identity::new(
            MyIdentityData {
                first: "foo".into(),
                last: "bar".into(),
            },
            Some(expiration),
        );

        assert_eq!("foo", identity.data::<MyIdentityData>().unwrap().first);
        assert_eq!("bar", identity.data::<MyIdentityData>().unwrap().last);
        assert_eq!(Some(expiration), identity.expiration());
    }
}