/**
 * Original work Copyright (c) 2018 PoC-Consortium
 * Modified work Copyright (c) 2019 Burst Apps Team
 */
/**
 * Converts/Encodes a String into Base64 (URI) encoded string. UTF-8 is supported.
 * Inverse function {@link convertBase64StringToString}
 * @param str The string to be converted
 * @param isURICompatible Determine whether the resulting string shall be URI compatible, or not. Default is `true`
 * @return {string} The Base64 String representing the input string. The string is already URI encoded, i.e. can be used directly in browsers
 *
 * @category conversion
 */
export declare const convertStringToBase64String: (str: string, isURICompatible?: boolean) => string;