Function switched_http_client 

pub fn switched_http_client(
    use_pool: impl Fn() -> bool + Send + Sync + 'static,
    pool_max_in_flight: impl Fn() -> usize + Send + Sync + 'static,
    pool_metrics: HttpPoolMetrics,
) -> impl HttpClient

Returns an HTTP client for use with the AWS SDK that sends each request through pooled_http_client if use_pool returns true when the request is sent, and through http_client otherwise.