bool shouldSelectAnotherHost(const Upstream::Host& candidate_host) override {

    return std::find(attempted_hosts_.begin(), attempted_hosts_.end(), &candidate_host) !=

           attempted_hosts_.end();

  }

  void onHostAttempted(Upstream::HostDescriptionConstSharedPtr attempted_host) override {

    attempted_hosts_.emplace_back(attempted_host.get());

  }