anchor.diff:  		Attributes :: radius_attributes:attributes() | binary(),
   		Result :: {ok, #subscriber{}} | {error, Reason},
   		Reason :: term().
  -%% @equiv add_subscriber(Identity, Password, Attributes, undefined, [], true, false)
  +%% @equiv add_subscriber(Identity, Password, Attributes, [], undefined, true, false)
   add_subscriber(Identity, Password, Attributes) ->
  -	add_subscriber(Identity, Password, Attributes, undefined, [], true, false).
  +	add_subscriber(Identity, Password, Attributes, [], undefined, true, false).
   
   -spec add_subscriber(Identity, Password, Attributes, Buckets) -> Result
   	when 
  
positive.code: 		Buckets :: [#bucket{}],
  		Result :: {ok, #subscriber{}} | {error, Reason},
  		Reason :: term().
  %% @equiv add_subscriber(Identity, Password, Attributes, Product, Buckets, true, false)
  add_subscriber(Identity, Password, Attributes, Buckets) ->
  	add_subscriber(Identity, Password, Attributes, Buckets, undefined, true, false).
  
  -spec add_subscriber(Identity, Password, Attributes,
  		Product, Buckets, EnabledStatus, MultiSessions) -> Result
  	when 
  		Identity :: string() | binary() | undefined,
  		Password :: string() | binary() | undefined,
  
negative.code: 		{aborted, Reason} ->
  			{error, Reason}
  	end;
  add_subscriber(Identity, Password, Attributes, Buckets, Product, EnabledStatus, MultiSession)
  		when is_binary(Identity), is_binary(Password), is_list(Attributes),
  		is_list(Buckets), is_boolean(EnabledStatus), is_boolean(MultiSession) ->
  	F1 = fun() ->
  