/**
 * Creates a new URL by combining the baseURL with the requestedURL,
 * only when the requestedURL is not already an absolute URL.
 * If the requestURL is absolute, this function returns the requestedURL untouched.
 *
 * @param {string} baseURL The base URL
 * @param {string} requestedURL Absolute or relative URL to combine
 *
 * @returns {string} The combined full path
 */
export default function (baseURL?: string, requestedURL?: string, allowAbsoluteUrls?: boolean): string | undefined;