import { DownloadProgressCallback } from './types';
declare type ReturnTypeOption = 'blob' | 'uri';
declare type ReturnType = Blob | string;
interface DownloaderOptions {
    returnType?: ReturnTypeOption;
    workerUrl?: string;
}
declare class Downloader {
    private readonly workerUrl;
    private readonly hasWorkers;
    private readonly returnType;
    constructor({ returnType, workerUrl }?: DownloaderOptions);
    download(resourceUri: string, onDownloadProgress?: DownloadProgressCallback): Promise<ReturnType>;
    private formatResult;
    private checkWorkerAvailability;
}
export default Downloader;