code: func (s *Stack) UnregisterRawTransportEndpoint(nicID tcpip.NICID, netProto tcpip.NetworkProtocolNumber, transProto tcpip.TransportProtocolNumber, ep RawTransportEndpoint) {
  	if nicID == 0 {
  		s.demux.unregisterRawEndpoint(netProto, transProto, ep)
  		return
  	}
  
  	s.mu.RLock()
  	defer s.mu.RUnlock()
  
  	nic := s.nics[nicID]
  	if nic != nil {
  		nic.demux.unregisterRawEndpoint(netProto, transProto, ep)
  	}
  }
docs: // UnregisterRawTransportEndpoint removes the endpoint for the transport
  // protocol from the stack transport dispatcher.