export declare class EdgeHeaders implements Headers {
    protected readonly map: Map<string, string>;
    constructor(init?: HeadersInit | Map<string, string>);
    entries(): IterableIterator<[string, string]>;
    keys(): IterableIterator<string>;
    values(): IterableIterator<string>;
    append(name: string, value: string): void;
    delete(name: string): void;
    forEach(callback: (value: string, key: string, parent: Headers) => void, thisArg?: any): void;
    get(name: string): string | null;
    has(name: string): boolean;
    set(name: string, value: string): void;
    [Symbol.iterator](): IterableIterator<[string, string]>;
}
export declare function asHeaders(h: HeadersInit | undefined, default_headers?: Record<string, string>): Headers;