interface listenerType {
    callback: any;
    guid?: string;
    time?: number;
}
export declare class CallbackListener {
    private listeners;
    private static instance;
    static getInstance(): CallbackListener;
    findListener(guid: string): listenerType;
    addListener(listener: listenerType): string;
    removeListener(guid: string): void;
    private randomString;
}
export {};