anchor.diff:  
   -define(TABLE, ?MODULE).
   
  --record(st, {ttl = 5000}).
  +-record(st, {ttl = 5000, waiters = [], workers = []}).
   
   -record(cache, {name, value, tref, time, ttl}).
   
  
positive.code:     restart_timers(S#st.ttl),
      {ok, #st{}}.
  
  handle_call(_, _, S) ->
      {reply, error, S}.
  
  
negative.code: -export([start_link/0]).
  
  -export([read/1,   %% (Name) -> {ok, Value} | error
  	 read/5,   %% (Name, Mod, Type, Ref, DataPoints) ->
  	           %%     {ok,Value} | unavailable
  	 write/2,  %% (Name, Value) -> ok
  	 write/3,  %% (Name, Value, TTL) -> ok
  	 delete/1
  