import { EventEmitter as ee } from 'events';
export declare const isNodeJs: boolean;
export declare const isBrowser: boolean;
export declare const WebSocketImpl: {
    new (url: string | URL, protocols?: string | string[]): WebSocket;
    prototype: WebSocket;
    readonly CONNECTING: 0;
    readonly OPEN: 1;
    readonly CLOSING: 2;
    readonly CLOSED: 3;
} | typeof import("ws");
export declare const EventEmitter: typeof ee;