code: func NewInjectableEndpoint(routes map[tcpip.Address]stack.InjectableLinkEndpoint) (tcpip.LinkEndpointID, *InjectableEndpoint) {
  	e := &InjectableEndpoint{
  		routes: routes,
  	}
  	return stack.RegisterLinkEndpoint(e), e
  }
docs: // NewInjectableEndpoint creates a new multi-endpoint injectable endpoint.