/**
 * Request header access.
 *
 * Header names are normalized to lowercase and their values collapsed to a
 * single string when the header store is built (see `normalizeHeaders` in
 * `./request`), so every lookup here resolves the canonical lowercase name and
 * never has to deal with a multi-value header.
 */
export interface HttpHeaderCarrier {
    readonly headers: Record<string, string>;
}
export declare function getHeaderValue(headers: Record<string, string>, name: string): string | undefined;
export declare function getRequestHeader(request: HttpHeaderCarrier, name: string): string | undefined;
/**
 * Resolves a header for a route parameter, whose declared name may be
 * camelCase: `userAgent` matches `useragent`, then `user-agent`, then
 * `x-user-agent`.
 */
export declare function getRequestHeaderForParameter(request: HttpHeaderCarrier, name: string): string | undefined;
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