* concurrently, returning once any connection connects successfully.
     *
     * This implements Happy Eyeballs ([RFC 6555][rfc_6555]), balancing connect latency vs.
     * wasted resources.
     *
     * Defaults to enabled, call with [fastFallback] = false to revert to 4.x behaviour.
     *
     * [rfc_6555]: https://datatracker.ietf.org/doc/html/rfc6555
     */
    fun fastFallback(fastFallback: Boolean) =
      apply {

 * is similar policy for all of the 1.1 million Unicode code points. Note that some code points such
 * as "\ud83c\udf69" are not mapped and cannot be used in a hostname.
 *
 * [Punycode](http://ietf.org/rfc/rfc3492.txt) converts a Unicode string to an ASCII string to make
 * international domain names work everywhere. For example, "σ" encodes as "xn--4xa". The encoded