declare class Headers extends globalThis.Headers { getAll(key: 'set-cookie'): string[] } declare class Request extends globalThis.Request { readonly headers: Headers } declare class Response extends globalThis.Response { readonly headers: Headers } declare const fetchImplementation: typeof fetch declare const FileConstructor: typeof File declare const FormDataConstructor: typeof FormData export { FileConstructor as File, FormDataConstructor as FormData, Headers, Request, Response, fetchImplementation as fetch };