anchor.diff:  
   %% API.
   -export([start_link/0]).
  --export([join_xnest/1]).
  +-export([get_xnest/1]).
   -export([get_xnest_count/0]).
   
   %% gen_server.
  
positive.code: %% Internal.
  %%------------------------------------------------------------------------------------------------
  
  % Internal functions should be here.
  
  
negative.code: 
  
  -define(TAB, ?MODULE).
  -define(PID_INDEX, pid_to_name).
  
  -record(state, {
  }).
  
  %%------------------------------------------------------------------------------------------------
  