  void handshakeErr(
      AsyncSSLSocket* /* socket */,
      const AsyncSocketException& ex) noexcept override {
    VLOG(1) << "client handshakeErr: " << ex.what();
    fail(ex);
    delete this;
  }
  void handshakeErr(
      AsyncSSLSocket*  ,
      const AsyncSocketException& ex) noexcept override {
    VLOG(1) << "client handshakeErr: " << ex.what();
    fail(ex);
    delete this;
  }