*  Fix: Recover gracefully if the TLS session returns an unexpected version (`NONE`) or cipher
    suite (`SSL_NULL_WITH_NULL_NULL`).
 *  Fix: Don't change Conscrypt configuration globally. We migrated from a process-wide setting to
    configuring only OkHttp's TLS sockets.
 *  Fix: Prefer TLSv1.2 where it is available. On certain older platforms it is necessary to opt-in
    to TLSv1.2.

      apply {
        this.taskRunner = taskRunner
      }

    /**
     * Sets the DNS service used to lookup IP addresses for hostnames.
     *
     * If unset, the [system-wide default][Dns.SYSTEM] DNS will be used.
     */
    fun dns(dns: Dns) =
      apply {
        if (dns != this.dns) {
          this.routeDatabase = null
        }
        this.dns = dns
      }