anchor.diff:  -export([handle_call/3]).
   
   -export([add/0]).
  --export([add/1]).
  +-export([remove/1]).
  +-export([online/1]).
  +-export([offline/1]).
   -export([is_on/1]).
   -export([lookup/1]).
  --export([remove/1]).
   -export([run/0]).
   -export([run/1]).
   
  
positive.code: lookup(Id) ->
  	Reply = gen_server:call(?MODULE, {lookup, Id}).
  
  remove(Id) ->
  	Reply = gen_server:call(?MODULE, {remove, Id}).
  
  run() ->
  	Reply = gen_server:call(?MODULE, {run, 1000}).
  
  run(IntervalMSec) ->
  	Reply = gen_server:call(?MODULE, {run, IntervalMSec}).
  
  %%
  %% Behaviors
  
negative.code: add() ->
  	Reply = gen_server:call(?MODULE, {add, auto_increment}).
  
  remove(Id) ->
  	Reply = gen_server:call(?MODULE, {remove, Id}).
  
  online(Id) ->
  	Reply = gen_server:call(?MODULE, {online, Id}).
  
  offline(Id) ->
  	Reply = gen_server:call(?MODULE, {offline, Id}).
  
  is_on(Id) ->
  	Reply = gen_server:call(?MODULE, {is_on, Id}).
  