anchor.diff:  -define(VALID_NAME_REGEX, "^[a-z0-9\-_]+$").
   
   validate_group_name(undefined) ->
  -    missing;
  +    invalid;
   validate_group_name(Name) ->
       {ok, CompiledRegex} = re:compile(?VALID_NAME_REGEX),
       case re:run(Name, CompiledRegex) of
  
positive.code:     JsonError = {[{<<"error">>, [Msg]}]},
      {{halt, 400}, chef_wm_util:set_json_body(Req, JsonError), State}.
  
  
negative.code: auth_info('GET', Req, State ) ->
      {{container, group}, Req, State};
  auth_info('POST', Req, State = #base_state{resource_state = #group_state{group_data = Json}}) ->
      case validate_group_name(fetch_id_name_from_json(Json)) of
          valid ->
              {{create_in_container, group}, Req, State};
          invalid ->
              group_name_invalid(Req, State)
      end.
  
  resource_exists(Req, State) ->
      {true, Req, State}.
  
  create_path(Req, #base_state{resource_state = #group_state{group_data = GroupData}} = State) ->
      Name = fetch_id_name_from_json(GroupData),
      {binary_to_list(Name), Req, State}.
  
  from_json(Req, #base_state{resource_state = #group_state{group_data = GroupData,
  