anchor.diff:  %% Starts memory cleaning.
   %% @end
   %%--------------------------------------------------------------------
  --spec start_memory_cleaning(LastCleaningPid :: pid(), MemUsage :: float(), State :: #state{}) -> #state{}.
  +-spec start_memory_cleaning(LastCleaningPid :: pid(), MemUsage :: float() | undefined, State :: #state{}) -> #state{}.
   start_memory_cleaning(LastCleaningPid, MemUsage, State) ->
       case LastCleaningPid of
           undefined ->
  
positive.code:             {ok, CleaningPeriod} = application:get_env(?CLUSTER_WORKER_APP_NAME, clear_cache_max_period_ms),
              case timer:now_diff(Now, Last) >= 1000000 * CleaningPeriod of
                  true ->
                      start_memory_cleaning(LastCleaningPid, MemUsage, State);
                  _ ->
                      State
              end
  
negative.code:             {error, E2}
      end.
  
  %%--------------------------------------------------------------------
  %% @private
  %% @doc
  