import { SDKUtils } from '../models/common';
export declare class SDKViewportImpressions {
    private tracker;
    private isInitialized;
    initialize(sdkUtils: SDKUtils): void;
    trackElement(element: HTMLElement, productId: string, position: number, sdkUtils: SDKUtils): void;
    onContextChange(): void;
    destroy(): void;
    private formatNarrowBy;
    private reportImpressions;
    private sendImpressionRequest;
}