interface listenerType {
    callback: any;
    guid?: string;
    time?: number;
}
/**
 * @public
 * @class CallbackListener
 */
export declare class CallbackListener {
    private listeners;
    private static instance;
    /**
     * @static
     * @public
     * @function getInstance
     * @returns {CallbackListener}
     */
    static getInstance(): CallbackListener;
    /**
     * @public
     * @function findListener
     * @param {string} guid
     * @returns {listenerType}
     */
    findListener(guid: string): listenerType;
    /**
     * @public
     * @function addListener
     * @param {listenerType} listener
     * @returns {string}
     */
    addListener(listener: listenerType): string;
    /**
     * @public
     * @function removeListener
     * @param {string} guid
     * @returns {void}
     */
    removeListener(guid: string): void;
    /**
     * @private
     * @function randomString
     * @param {number} e
     * @returns {string}
     */
    private randomString;
}
export {};