/**
 * Create a domainOverride callback for an ID module, closing over
 * an instance of StorageManager.
 *
 * The domainOverride function, given document.domain, will return
 * the topmost domain we are able to set a cookie on. For example,
 * given subdomain.example.com, it would return example.com.
 *
 * @param storage e.g. from getStorageManager()
 * @param {string} moduleName the name of the module using this function
 * @returns {function(): string}
 */
export function domainOverrideToRootDomain(storage: any, moduleName: string): () => string;