import { HeadersDict, HeaderValue, NumericalHeadersDict, NumericalHeaderValue } from "../types";
export interface HeaderHandler {
    setHeaders(headers: NumericalHeadersDict): this;
    setHeader(key: string, value: NumericalHeaderValue): this;
    set(key: string, value: NumericalHeaderValue): this;
    appendHeader(key: string, value: NumericalHeaderValue): this;
    append(key: string, value: NumericalHeaderValue): this;
    hasHeader(key: string): string | false;
    has(key: string): string | false;
    removeHeader(key: string): this;
    remove(key: string): this;
    getHeader<T extends HeaderValue = HeaderValue>(key: string): T | undefined;
    get<T extends HeaderValue = HeaderValue>(key: string): T | undefined;
}
export declare function initHeaderHandler<T extends HeaderHandler>(target: T, getHeaders: (this: any) => HeadersDict, setHeaders: (this: any) => HeadersDict): void;