/**
 * @file class Headers 实现
 * @desc 参考 https://github.com/github/fetch
 */
export type HeadersInit = [string, string][] | Record<string, string> | Headers;
export default class Headers {
    private map;
    constructor(headers?: HeadersInit);
    append(name: string, value: string): void;
    delete(name: string): void;
    get(name: string): string | null;
    has(name: string): boolean;
    set(name: string, value: string): void;
    forEach(callback: (value: string, key: string, parent: Headers) => void, thisArg?: any): void;
    keys(): {
        next: () => {
            done: boolean;
            value: string | undefined;
        };
        [Symbol.iterator]: () => any;
    };
    values(): {
        next: () => {
            done: boolean;
            value: string | undefined;
        };
        [Symbol.iterator]: () => any;
    };
    entries(): {
        next: () => {
            done: boolean;
            value: [string, string] | undefined;
        };
        [Symbol.iterator]: () => any;
    };
}