interface__internal.FallbackHeadersinterface FallbackHeaders[Symbol.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): null | string;getSetCookie(): string[];has(name: string): boolean;keys(): SpecIterableIterator<string>;set(name: string,value: string): void;values(): SpecIterableIterator<string>;