/**
 * Copyright 2024 Google LLC.
 * Copyright (c) Microsoft Corporation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/**
 * Encodes a string to base64.
 *
 * Uses the native Web API if available, otherwise falls back to a NodeJS Buffer.
 * @param {string} base64Str
 * @return {string}
 */
export declare function base64ToString(base64Str: string): string;