anchor.diff:      {ok, Client2} = cowboy_client:request(Method, build_url(<<"/">>, Config), Headers, Client),
       cowboy_client:response(Client2).
   
  +preflight(Headers, Config) ->
  +    request(<<"OPTIONS">>, Headers, Config).
  +
   %% Tests
   
  -simple_no_origin_get(Config) ->
  +standard_no_origin_get(Config) ->
       {ok, 200, Headers, _} = request(<<"GET">>, [], Config),
       false = lists:keyfind(<<"access-control-allow-origin">>, 1, Headers).
   
  -simple_get(Config) ->
  +standard_no_origin_options(Config) ->
  +    {ok, 200, Headers, _} = request(<<"OPTIONS">>, [], Config),
  +    false = lists:keyfind(<<"access-control-allow-origin">>, 1, Headers).
  +
  +standard_get(Config) ->
       Origin = <<"http://banned.example.com">>,
       {ok, 200, Headers, _} = request(<<"GET">>, [{<<"Origin">>, Origin}], Config),
       false = lists:keyfind(<<"access-control-allow-origin">>, 1, Headers).
   
  +standard_options(Config) ->
  +    Origin = <<"http://banned.example.com">>,
  +    {ok, 200, Headers, _} = request(<<"OPTIONS">>, [{<<"Origin">>, Origin}], Config),
  +    false = lists:keyfind(<<"access-control-allow-origin">>, 1, Headers).
  +
   simple_allowed_get(Config) ->
       Origin = <<"http://allowed.example.com">>,
       {ok, 200, Headers, _} =
  
positive.code:     {_, Origin} = lists:keyfind(<<"access-control-allow-origin">>, 1, Headers),
      {_, <<"x-exposed">>} = lists:keyfind(<<"access-control-expose-headers">>, 1, Headers),
      {_, <<"true">>} = lists:keyfind(<<"access-control-allow-credentials">>, 1, Headers).
  
negative.code: -export([end_per_group/2]).
  
  %% tests
  -export([standard_no_origin_get/1]).
  -export([standard_no_origin_options/1]).
  -export([standard_get/1]).
  -export([standard_options/1]).
  -export([simple_allowed_get/1]).
  -export([simple_allowed_credentials_get/1]).
  -export([preflight_method/1]).
  -export([preflight_no_method/1]).
  -export([preflight_allowed_method/1]).
  -export([preflight_credentials/1]).
  -export([preflight_header/1]).
  -export([preflight_allowed_header/1]).
  -export([preflight_allowed_header_webkit/1]).
  
  all() ->
      [
  