anchor.diff:  %% Utilities
   %%
   
  -gen_token() -> crypto:rand_bytes(?BYTES_OF_TOKEN).
  +gen_token() ->
  +	#token{token = crypto:rand_bytes(?BYTES_OF_TOKEN),
  +		expire_unixtime = 0}.
   
  +gen_token(ExpireUnixtime) ->
  +	#token{token = crypto:rand_bytes(?BYTES_OF_TOKEN),
  +		expire_unixtime = ExpireUnixtime}.
   
   %%
   %% Behaviors
  
positive.code: %%
  %% APIs
  %%
  test() -> ng.
  
  add(Id) ->
  	Reply = gen_server:call(?MODULE, {add, Id}).
  
  remove_all() ->
  	Reply = gen_server:call(?MODULE, {remove_all}).
  
negative.code: 		{ok, Fetched1} -> true;
  		{error, notfound} -> false
  	end.
  
  impl_online(Pid, Id, Token) when is_list(Id) ->
  	BinId = erlang:list_to_binary(Id),
  