anchor.diff:  %%                         {stop, Reason}
   %% Description: Initiates the server
   %%--------------------------------------------------------------------
  +-spec init(list()) -> {ok, #state{}}.
   init([]) ->
       {ok, #state{start=erlang:now(), map=gb_trees:empty()}}.
   
  
positive.code: -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
           terminate/2, code_change/3]).
  
  -record(state, {start, map}).
  
  %%====================================================================
  %% API
  
negative.code: %% Func: code_change(OldVsn, State, Extra) -> {ok, NewState}
  %% Description: Convert process state when code is changed
  %%--------------------------------------------------------------------
  -spec code_change(any(), #state{}, any()) -> {ok, #state{}}.
  code_change(_OldVsn, State, _Extra) ->
      {ok, State}.
  
  