code: func (c *Conn) ConnectionState() ConnectionState {
  	c.handshakeMutex.Lock()
  	defer c.handshakeMutex.Unlock()
  
  	var state ConnectionState
  	state.HandshakeComplete = c.handshakeComplete
  	if c.handshakeComplete {
  		state.Version = c.vers
  		state.NegotiatedProtocol = c.clientProtocol
  		state.DidResume = c.didResume
  		state.NegotiatedProtocolIsMutual = !c.clientProtocolFallback
  		state.CipherSuite = c.cipherSuite
  		state.PeerCertificates = c.peerCertificates
  		state.VerifiedChains = c.verifiedChains
  		state.ServerName = c.serverName
  		state.SignedCertificateTimestamps = c.scts
  		state.OCSPResponse = c.ocspResponse
  		if !c.didResume {
  			state.TLSUnique = c.firstFinished[:]
  		}
  	}
  
  	return state
  }
docs: // ConnectionState returns basic TLS details about the connection.