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: config.rs
    path of file: ./repos/aws-sdk-rust/sdk/cognitoidentity/src
    
    the code of the file until where you have to start completion: // Code generated by software.amazon.smithy.rust.codegen.smithy-rs. DO NOT EDIT.

/// Configuration for a aws_sdk_cognitoidentity service client.
///
///
/// Service configuration allows for customization of endpoints, region, credentials providers,
/// and retry configuration. Generally, it is constructed automatically for you from a shared
/// configuration loaded by the `aws-config` crate. For example:
///
/// ```ignore
/// // Load a shared config from the environment
/// let shared_config = aws_config::from_env().load().await;
/// // The client constructor automatically converts the shared config into the service config
/// let client = Client::new(&shared_config);
/// ```
///
/// The service config can also be constructed manually using its builder.
///
#[derive(::std::clone::Clone, ::std::fmt::Debug)]
pub struct Config {
    // Both `config` and `cloneable` are the same config, but the cloneable one
    // is kept around so that it is possible to
    
    /// # fn example() {
    /// use aws_smithy_runtime_api::client::interceptors::context::phase::BeforeTransmit;
    /// use aws_smithy_runtime_api::client::interceptors::{Interceptor, InterceptorContext, SharedInterceptor};
    /// use aws_smithy_types::config_bag::ConfigBag;
    /// use aws_sdk_cognitoidentity::config::{Builder, Config};
    ///
    /// fn base_url() -> String {
    ///     // ...
    ///     # String::new()
    /// }
    ///
    /// fn modify_request_uri(builder: &mut Builder) {
    ///     #[derive(Debug)]
    ///     pub struct UriModifierInterceptor;
    ///     impl Intercept for UriModifierInterceptor {
    ///         fn modify_before_signing(
    ///             &self,
    ///             context: &mut InterceptorContext<BeforeTransmit>,
    ///             _cfg: &mut ConfigBag,
    ///         ) -> Result<(), aws_smithy_runtime_api::client::interceptors::BoxError> {
    ///             let request = context.request_mut();
    ///             let uri = format!("{}{}", base_url(), request.uri().path());
    ///             *request.uri_mut() = uri.parse()?;
    ///
    ///             Ok(())
    ///         }
    ///     }
    ///     builder.push_interceptor(SharedInterceptor::new(UriModifierInterceptor));
    /// }
    ///
    /// let mut builder = Config::builder();
    /// modify_request_uri(&mut builder);
    /// let config = builder.build();
    /// # }