export declare class Base64Decode {
    /**
     * Returns a URL-safe plaintext decoded string from b64 encoded input.
     */
    static decode(input: string): string;
    /**
     * Decodes base64 into Uint8Array
     */
    private static base64DecToArr;
    /**
     * Base64 string to array decoding helper
     */
    private static b64ToUint6;
}