Interface Headers

interface Headers {
    "[iterator]": () => SpecIterableIterator<[string, string]>;
    append: (name: string, value: string) => void;
    delete: (name: string) => void;
    entries: () => SpecIterableIterator<[string, string]>;
    forEach: (
        callbackfn: (value: string, key: string, iterable: Headers) => void,
        thisArg?: unknown,
    ) => void;
    get: (name: string) => string;
    getSetCookie: () => string[];
    has: (name: string) => boolean;
    keys: () => SpecIterableIterator<string>;
    set: (name: string, value: string) => void;
    values: () => SpecIterableIterator<string>;
}