import { HttpHeaders } from '@angular/common/http';
export declare class HttpHeadersBuilder {
    private _headers;
    private constructor();
    static fresh(): HttpHeadersBuilder;
    static fromHeaders(headers: HttpHeadersBuilder | HttpHeaders | {
        [name: string]: string | string[];
    }): HttpHeadersBuilder;
    private static validateArgs;
    build(): HttpHeaders;
    readonly headers: HttpHeaders;
    append(key: string, value: string | string[]): this;
    set(key: string, value: string | string[]): this;
    aIM(value: string | string[]): HttpHeadersBuilder;
    accept(value: string | string[]): HttpHeadersBuilder;
    acceptCharset(value: string | string[]): HttpHeadersBuilder;
    acceptDatetime(value: string | string[]): HttpHeadersBuilder;
    acceptEncoding(value: string | string[]): HttpHeadersBuilder;
    acceptLanguage(value: string | string[]): HttpHeadersBuilder;
    accessControlRequestMethod(value: string | string[]): HttpHeadersBuilder;
    accessControlRequestHeaders(value: string | string[]): HttpHeadersBuilder;
    authorization(value: string | string[]): HttpHeadersBuilder;
    cacheControl(value: string | string[]): HttpHeadersBuilder;
    connection(value: string | string[]): HttpHeadersBuilder;
    contentEncoding(value: string | string[]): HttpHeadersBuilder;
    contentLength(value: string | string[]): HttpHeadersBuilder;
    contentMD5(value: string | string[]): HttpHeadersBuilder;
    contentType(value: string | string[]): HttpHeadersBuilder;
    cookie(value: string | string[]): HttpHeadersBuilder;
    date(value: string | string[]): HttpHeadersBuilder;
    expect(value: string | string[]): HttpHeadersBuilder;
    forwarded(value: string | string[]): HttpHeadersBuilder;
    from(value: string | string[]): HttpHeadersBuilder;
    host(value: string | string[]): HttpHeadersBuilder;
    HTTP2Settings(value: string | string[]): HttpHeadersBuilder;
    ifMatch(value: string | string[]): HttpHeadersBuilder;
    ifModifiedSince(value: string | string[]): HttpHeadersBuilder;
    ifNoneMatch(value: string | string[]): HttpHeadersBuilder;
    ifRange(value: string | string[]): HttpHeadersBuilder;
    ifUnmodifiedSince(value: string | string[]): HttpHeadersBuilder;
    maxForwards(value: string | string[]): HttpHeadersBuilder;
    origin(value: string | string[]): HttpHeadersBuilder;
    pragma(value: string | string[]): HttpHeadersBuilder;
    prefer(value: string | string[]): HttpHeadersBuilder;
    proxyAuthorization(value: string | string[]): HttpHeadersBuilder;
    range(value: string | string[]): HttpHeadersBuilder;
    referer(value: string | string[]): HttpHeadersBuilder;
    TE(value: string | string[]): HttpHeadersBuilder;
    trailer(value: string | string[]): HttpHeadersBuilder;
    transferEncoding(value: string | string[]): HttpHeadersBuilder;
    userAgent(value: string | string[]): HttpHeadersBuilder;
    upgrade(value: string | string[]): HttpHeadersBuilder;
    via(value: string | string[]): HttpHeadersBuilder;
    warning(value: string | string[]): HttpHeadersBuilder;
    addAll(headers: HttpHeadersBuilder | HttpHeaders | {
        [name: string]: string | string[];
    }): this;
}