anchor.diff:      Now = now(),
       Elapsed = trunc(timer:now_diff(Now, State#state.start_time) / 1000000),
       Window  = trunc(timer:now_diff(Now, State#state.last_write_time) / 1000000),
  -    
  +
       %% Time to report latency data to our CSV files
       {Oks, Errors} = lists:foldl(fun(Op, {TotalOks, TotalErrors}) ->
                                           {Oks, Errors} = report_latency(Elapsed, Window, Op),
  
positive.code:     erlang:put({latencies, Op}, Hist),
      {reply, ok, State};
  handle_call({op, Op, {error, Reason}, _ElapsedUs}, _From, State) ->
      ?ERROR("~p: ~p\n", [Op, Reason]),
      increment_error_counter(Op),
      increment_error_counter({Op, Reason}),
      {reply, ok, State}.
  
  handle_cast(_, State) ->
      {noreply, State}.
  
negative.code:                  start_time,
                   last_write_time,
                   report_interval,
                   errors_since_last_report = false,
                   summary_file}).
  
  %% Tracks latencies up to 5 secs w/ 250 us resolution
  