export declare class MessageEventPolyfill<T = any> extends Event {
    readonly data: T;
    readonly origin: string;
    readonly lastEventId: string;
    readonly source: MessageEventSource | null;
    readonly ports: ReadonlyArray<MessagePort>;
    constructor(type: string, init?: {
        data?: T;
        origin?: string;
        lastEventId?: string;
        source?: MessageEventSource | null;
        ports?: MessagePort[];
    });
    /** @deprecated */
    initMessageEvent(_type: string, _bubbles?: boolean, _cancelable?: boolean, _data?: any, _origin?: string, _lastEventId?: string, _source?: MessageEventSource | null, _ports?: MessagePort[]): void;
}
//# sourceMappingURL=polyfill.d.ts.map