anchor.diff:  %% postcondition
   %% =======================================================
   
  -postcondition(State, {call, _, create_map, [Json, InState]}, {ok, "201", Heads, Body}) ->
  +postcondition(State, {call, _, create_map, [Json, InState]}, {ok, "201", Heads, Body} = Goop) ->
   	?assertNotEqual(undefined, proplists:get_value("Location", Heads)),
   	?assert(assert_body(Json, Body)),
   	true;
  
positive.code: 
  create_map(Json, #state{url = undefined}) ->
  	Url = "http://localhost:9093/map",
  	Binary = jsx:to_json(Json),
  	ibrowse:send_req(Url, [?cookie, ?accepts, ?contenttype], put, Binary).
  
  destroy_map(#state{url = Url}) ->
  
negative.code: 	?LET(N,
  	list(
  		frequency([
  			{1, 9},
  			{8, integer(32, 126)},
  			{5, char()}
  		])
  	), unicode:characters_to_binary(N)).
  
  g_color() ->
  	oneof([
  