anchor.diff:                         State).
   
   increment_stat_refills(Token, State) ->
  +    lager:info("Refill token ~p", [Token]),
       update_stat_window(Token,
                          fun(Stat) -> Stat#bg_stat_hist{refills=1+Stat#bg_stat_hist.refills} end,
                          default_refill(Token, State),
  
positive.code: %%      then the extra locks are released by killing processes with reason `max_concurrency'.
  %%      If `false', then the processes holding the extra locks are aloud to do so until they
  %%      are released.
  -spec set_concurrency_limit(bg_lock(), bg_concurrency_limit(), boolean()) -> bg_concurrency_limit().
  set_concurrency_limit(Lock, Limit, Kill) ->
      gen_server:call(?MODULE, {set_concurrency_limit, Lock, Limit, Kill}, infinity).
  
  
negative.code:                      State).
  
  update_limit(Resource, Limit, Default, State) ->
      lager:info("Set concurrency ~p <- ~p", [Resource, Limit]),
      update_resource_info(Resource,
                           fun(Info) -> Info#resource_info{limit=Limit} end,
                           Default#resource_info{limit=Limit},
  