/**
   * Returns a string with the URL hostname, socket IP address, and socket port, like one of these:
   *
   *  * `example.com:80 at 1.2.3.4:8888`
   *  * `example.com:443 via proxy [::1]:8888`
   *
   * This omits duplicate information when possible.
   */
  override fun toString(): String {
    return buildString {
      val addressHostname = address.url.host // Already in canonical form.