private function printStatistics($startTime)
{
$duration = time() - $startTime;
$hours = intval($duration / 3600);
$minutes = intval(($duration - $hours * 3600) / 60);
$seconds = $duration % 60;
echo PHP_EOL, 'Time: ', sprintf('%d:%02d:%02d', $hours, $minutes, $seconds);
if (function_exists('memory_get_peak_usage')) {
$memory = memory_get_peak_usage(true) / (1024 * 1024);
printf('; Memory: %4.2fMb', $memory);
}
echo PHP_EOL;
}