export interface BlockOptions {
    dialogText?: string;
}
/**
 * This class is a surger to handle window beforeunload event.
 *
 * Example .
 * ```javascript
 * beforeunload.block(); // block user exit browser.
 *
 * doSomething()
 *
 * beforeunload.unblock(); // unblock user exit browser.
 * ```
 */
declare class Beforeunload {
    private onbeforeunload?;
    block(options?: BlockOptions): void;
    unblock(): void;
}
declare const Instance: Beforeunload;
export default Instance;