code: func (d *transportDemuxer) unregisterEndpoint(netProtos []tcpip.NetworkProtocolNumber, protocol tcpip.TransportProtocolNumber, id TransportEndpointID, ep TransportEndpoint) {
  	for _, n := range netProtos {
  		if eps, ok := d.protocol[protocolIDs{n, protocol}]; ok {
  			eps.unregisterEndpoint(id, ep)
  		}
  	}
  }
docs: // unregisterEndpoint unregisters the endpoint with the given id such that it
  // won't receive any more packets.