anchor.diff:  	FileName = Directory ++ "/" ++ Id,
   	read_ipdr(FileName, MaxItems).
   	
  --spec get_usagespec() -> Result
  +-spec get_usagespec(Query) -> Result
   	when
  +		Query :: [{Key :: string(), Value :: string()}],
   		Result :: {ok, Headers :: [tuple()], Body :: iolist()}.
   %% @doc Body producing function for
   %% 	`GET /usageManagement/v1/usageSpecification'
   %% 	requests.
  -get_usagespec() ->
  +get_usagespec([] = _Query) ->
   	Headers = [{content_type, "application/json"}],
   	Body = mochijson:encode({array, [spec_aaa_auth(),
   			spec_aaa_acct(), spec_public_wlan()]}),
   	{ok, Headers, Body}.
   
  --spec get_usagespec(Id) -> Result
  +-spec get_usagespec(Id, Query) -> Result
   	when
   		Id :: string(),
  +		Query :: [{Key :: string(), Value :: string()}],
   		Result :: {ok, Headers :: [tuple()], Body :: iolist()}
   				| {error, ErrorCode :: integer()}.
   %% @doc Body producing function for
   %% 	`GET /usageManagement/v1/usageSpecification/{id}'
   %% 	requests.
  -get_usagespec("AAAAccessUsageSpec") ->
  +get_usagespec("AAAAccessUsageSpec", [] = _Query) ->
   	Headers = [{content_type, "application/json"}],
   	Body = mochijson:encode(spec_aaa_auth()),
   	{ok, Headers, Body};
  -get_usagespec("AAAAccountingUsageSpec") ->
  +get_usagespec("AAAAccountingUsageSpec", [] = _Query) ->
   	Headers = [{content_type, "application/json"}],
   	Body = mochijson:encode(spec_aaa_acct()),
   	{ok, Headers, Body};
  -get_usagespec("PublicWLANAccessUsageSpec") ->
  +get_usagespec("PublicWLANAccessUsageSpec", [] = _Query) ->
   	Headers = [{content_type, "application/json"}],
   	Body = mochijson:encode(spec_public_wlan()),
   	{ok, Headers, Body};
  -get_usagespec(_Id) ->
  +get_usagespec(_Id, _Query) ->
   	{error, 404}.
   
   %%----------------------------------------------------------------------
  
positive.code: 			Headers = [{content_type, "application/json"},
  					{content_range, ContentRange}],
  			{ok, Headers, Body}
  	end.
  
  %% @hidden
  get_acct_usage(_Query) ->
  	{ok, MaxItems} = application:get_env(ocs, rest_page_size),
  	case ocs_log:last(ocs_acct, MaxItems) of
  		{error, _} ->
  
negative.code: 			Headers = [{content_type, "application/json"},
  					{content_range, ContentRange}],
  			{ok, Headers, Body}
  	end;
  get_acct_usage(_Query) ->
  	{error, 400}.
  
  