/**
 * A "modern" sleep statement.
 * @param ms The number of milliseconds to wait.
 */
export declare const delay: (ms: number) => Promise<unknown>;
/**
 *  Get the preferred scheme for a host
 * @param host An IP address or a domain name
 * @return 'http' or 'https'
 */
export declare const getPreferredUriScheme: (host: string) => "http" | "https";