anchor.diff:  
   %% API.
   
  --spec start_link() -> {ok, pid()}.
  -start_link() ->
  -	gen_server:start_link(?MODULE, [], []).
  +-spec start_link(Subject::binary(), Issuer::binary()) -> {ok, pid()}.
  +start_link(Subject, Issuer) ->
  +	gen_server:start_link(?MODULE, [Subject, Issuer], []).
   
   -spec set_user_info(UserInfo :: map(), Pid :: pid()) -> ok.
   set_user_info(Info, Pid) ->
  
positive.code: 
  %% gen_server.
  
  init([]) ->
  	{ok, #state{}, 5000}.
  
  handle_call({set_user_info,UserInfo}, _From, State) ->
      {reply, ok, State#state{user_info=UserInfo}};
  
negative.code: -include("tts.hrl").
  
  %% API.
  -export([start_link/2]).
  -export([set_user_info/2]).
  -export([get_user_info/1]).
  -export([get_credential_list/1]).
  