Method onConnection

examples/sudoku/server_basic.cc:37–42

 private:
  void onConnection(const TcpConnectionPtr& conn)
  {
    LOG_TRACE << conn->peerAddress().toIpPort() << " -> "
        << conn->localAddress().toIpPort() << " is "
        << (conn->connected() ? "UP" : "DOWN");
  }

  void onMessage(const TcpConnectionPtr& conn, Buffer* buf, Timestamp)
  {