anchor.diff:  	case call(Req, State, content_types_accepted) of
   		no_call ->
   			respond(Req, State, 415);
  -		{stop, Req2, HandlerState} ->
  -			terminate(Req2, State#state{handler_state=HandlerState});
  -		{Switch, Req2, HandlerState} when element(1, Switch) =:= switch_handler ->
  -			switch_handler(Switch, Req2, HandlerState);
  -		{CTA, Req2, HandlerState} ->
  +		{stop, Req2, State2} ->
  +			terminate(Req2, State2);
  +		{Switch, Req2, State2} when element(1, Switch) =:= switch_handler ->
  +			switch_handler(Switch, Req2, State2);
  +		{CTA, Req2, State2} ->
   			CTA2 = [normalize_content_types(P) || P <- CTA],
  -			State2 = State#state{handler_state=HandlerState},
   			try cowboy_req:parse_header(<<"content-type">>, Req2) of
   				ContentType ->
   					choose_content_type(Req2, State2, ContentType, CTA2)
  
positive.code: %% with Location the full new URI of the resource.
  moved_permanently(Req, State, OnFalse) ->
  	case call(Req, State, moved_permanently) of
  		{{true, Location}, Req2, HandlerState} ->
  			Req3 = cowboy_req:set_resp_header(
  				<<"location">>, Location, Req2),
  			respond(Req3, State#state{handler_state=HandlerState}, 301);
  		{false, Req2, HandlerState} ->
  			OnFalse(Req2, State#state{handler_state=HandlerState});
  		{stop, Req2, HandlerState} ->
  			terminate(Req2, State#state{handler_state=HandlerState});
  		{Switch, Req2, HandlerState} when element(1, Switch) =:= switch_handler ->
  			switch_handler(Switch, Req2, HandlerState);
  		no_call ->
  			OnFalse(Req, State)
  	end.
  
negative.code: 	case unsafe_call(Req, State, variances) of
  		no_call ->
  			{Variances, Req, State};
  		{HandlerVariances, Req2, State2} ->
  			{Variances ++ HandlerVariances, Req2, State2}
  	end.
  
  resource_exists(Req, State) ->
  