anchor.diff:      {false, Req, State}.
   
   allowed_methods(Req, State) ->
  -    {['GET', 'POST', 'HEAD'], Req, State}.
  +    {['GET', 'POST', 'DELETE', 'HEAD'], Req, State}.
   
   resource_exists(Req, State = #state{mode = collection}) ->
       {true, Req, State};
  
positive.code: 
  content_types_provided(Req, State) ->
      {[{"application/json", to_json}], Req, State}.
  
  to_json(Req, State = #state{mode = collection}) ->
      Context = State#state.context,
  
negative.code:               {Methods, _, _} = allowed_methods(req, state),
                ?assert(lists:member('GET', Methods)),
                ?assert(lists:member('POST', Methods)),
                ?assert(lists:member('DELETE', Methods)),
                ?assert(lists:member('HEAD', Methods)),
                ?assertEqual(4, erlang:length(Methods)),
                ok
        end
      ].
  