set will be used only if the pools with priority can't be used.
                  If multiple matching IPAddressPools are available it will check
                  for the availability of IPs sorting the matching IPAddressPools
                  by priority, starting from the highest to the lowest. If multiple
                  IPAddressPools have the same priority, choice will be random.

     *
     * * **Unreachable IP addresses.** If the URL's host has multiple IP addresses,
     *   failure to reach any individual IP address doesn't fail the overall request. This can
     *   increase availability of multi-homed services.
     *
     * * **Stale pooled connections.** The [ConnectionPool] reuses sockets
     *   to decrease request latency, but these connections will occasionally time out.
     *