code: func handshake(ctx context.Context, conn net.Conn) (*streamproto.Properties, error) {
  	log.Infof(ctx, "Beginning handshake.")
  	hs := handshakeProtocol{}
  	return hs.Handshake(ctx, conn)
  }
docs: // handshake handles the handshaking and registration of a single connection. If
  // the connection successfully handshakes, it will be registered as a stream and
  // supplied to the local streamParamsC; otherwise, it will be closed.
  //
  // The client connection opens with a handshake protocol. Once complete, the
  // connection itself becomes the stream.