import { WaterMarkConfig } from '../types';
export declare const observeWatermark: (watermark: HTMLDivElement, config: WaterMarkConfig) => Guard;
export declare class Guard {
    onchange: Function;
    config: WaterMarkConfig;
    parentElement: HTMLElement;
    observer: MutationObserver;
    element: HTMLElement;
    private elementHTML;
    private setIntervalId;
    private static config;
    constructor(element: HTMLElement, onchange: Function, config: WaterMarkConfig);
    start(): void;
    stop(): void;
    private _callback;
    private _reAddWatermark;
    private createWmByClone;
    private addWatermark;
    private getWatermark;
    private getTarget;
    private isEqualNode;
}