@Override
  public String toString() {
    final StringBuilder sb = new StringBuilder("Endpoint{");
    sb.append("host='").append(host).append('\'');
    sb.append(", udpPort=").append(udpPort);
    tcpPort.ifPresent(p -> sb.append(", getTcpPort=").append(p));
    sb.append('}');
    return sb.toString();
  }
If the tcp port is explicitly defined, return it. Otherwise, return the udp port assuming that
the tcp port should match the udp port.

@return The tcp port to use for this endpoint.
ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/discovery/Endpoint.java