anchor.diff:  -export([clear_oidc_state_nonce/1]).
   
   -export([is_user_agent/2]).
  +-export([is_same_ip/2]).
   -export([is_logged_in/1]).
   
   %% gen_server.
  
positive.code:     {reply, false, State, MA};
  handle_call(clear_oidc_state_nonce, _From, #state{ max_age=MA } = State) ->
      {reply, ok, State#state{oidc_state=cleared, oidc_nonce=cleared}, MA};
  handle_call({set_user_agent, UserAgent}, _From, #state{max_age=MA}=State) ->
      {reply, ok, State#state{user_agent=UserAgent}, MA};
  handle_call({is_user_agent, UserAgent}, _From,
              #state{user_agent=undefined, max_age=MA}=State) ->
      {reply, true, State#state{user_agent=UserAgent}, MA};
  
negative.code: 
  is_user_agent(UserAgent, Pid) ->
      gen_server:call(Pid, {is_user_agent, UserAgent}).
  
  is_same_ip(IP, Pid) ->
      gen_server:call(Pid, {is_same_ip, IP}).
  
  -spec get_oidc_state(Pid :: pid()) -> {ok, OidcState::binary()}.
  get_oidc_state(Pid) ->
  