import type { Readable } from "node:stream"; import type { APIGatewayProxyEventHeaders } from "aws-lambda"; export declare function normalizeLambdaIncomingHeaders(headers?: APIGatewayProxyEventHeaders): Record; export declare function normalizeLambdaOutgoingHeaders(headers: Record, stripCookies?: boolean): { [k: string]: string; }; export declare function normalizeLambdaOutgoingBody(body: BodyInit | ReadableStream | Buffer | Readable | Uint8Array | null | undefined, headers: Record): Promise<{ type: "text" | "binary"; body: string; }>;