/**
 * Converts an ArrayBuffer directly to base64, without any intermediate 'convert to string then
 * use window.btoa' step
 * @author Jon Leighton
 * @copyright Copyright 2011
 * @license MIT LICENSE
 * @link https://gist.github.com/jonleighton/958841
 */
export declare function base64ArrayBuffer(arrayBuffer: ArrayBuffer): string;