anchor.diff:  postcondition(State, {call, _, create_zone, [Put, Name, Next, _]}, {ok, "201", _, Body}) ->
   	#state{zones = Zones} = State,
   	NextZoneId = get_next(Next, Zones),
  +	Json = [{<<"next_zone_id">>, NextZoneId} | Put],
  +	Json2 = [{<<"name">>, Name} | proplists:delete(<<"name">>, Json)],
  +	Json3 = purge_undef(Json2),
  +	?assert(rpgb_test_util:assert_body(Json3, Body)),
  +	true;
  +
  +postcondition(State, {call, _, create_aura, [Put, Name, Next, Who, _]}, {ok, "201", _, Body}) ->
  +	#state{auras = Auras} = State,
  +	NextZoneId = get_next(Next, Auras),
   	Json = [{<<"next_zone_id">>, NextZoneId} | Put],
   	Json2 = [{<<"name">>, Name} | proplists:delete(<<"name">>, Json)],
   	Json3 = purge_undef(Json2),
  
positive.code: 	Json3 = purge_undef(Json2),
  	ibrowse:send_req(?zone_url, [owner_cookie(), ?accepts, ?contenttype], put, jsx:to_json(Json3)).
  
  delete_zone(Nth, State) ->
  	#state{zones = Zones} = State,
  	Zone = lists:nth(Nth, Zones),
  
negative.code: 			rpgb:splice(Zones, Next, 0, [{call, ?MODULE, decode_res, [Res]}])
  	end,
  	State#state{zones = Zones2};
  next_state(#state{auras = Auras} = State, Res, {call, _, create_aura, [_Put, _Name, Next, _Putter, _S]}) ->
  	Auras2 = if
  		is_atom(Next) ->
  			Auras ++ [{call, ?MODULE, decode_res, [Res]}];
  		true ->
  			rpgb:splice(Auras, Next, 0, [{call, ?MODULE, decode_res, [Res]}])
  	end,
  	State#state{auras = Auras2};
  next_state(#state{zones = Zones} = State, Res, {call, _, delete_zone, [Nth, _]}) ->
  	State#state{zones = rpgb:snip(Nth, Zones)};
  next_state(State, _Res, _Call) ->
  