export declare class SignatureEventTarget {
    private _et;
    constructor();
    addEventListener(type: string, listener: EventListenerOrEventListenerObject | null, options?: boolean | AddEventListenerOptions): void;
    dispatchEvent(event: Event): boolean;
    removeEventListener(type: string, callback: EventListenerOrEventListenerObject | null, options?: boolean | EventListenerOptions): void;
}