import { HttpRequest, HttpResponse, Middleware } from '../../types';
/**
 * Middleware injects a UUID string to `amz-sdk-invocation-id` header.
 * if the header is not set already. This header is helpful to provide
 * observability to group the requests caused by automatic retry.
 *
 * This middleware is standalone because of extra UUID dependency, we will
 * NOT use this middleware for API categories.
 *
 * Ref: https://sdk.amazonaws.com/kotlin/api/smithy-kotlin/api/1.0.9/http-client/aws.smithy.kotlin.runtime.http.operation/-http-operation-context/-sdk-invocation-id.html
 */
export declare const amzSdkInvocationIdHeaderMiddlewareFactory: Middleware<HttpRequest, HttpResponse, object>;