public static function print_timer($timer, $label = 'Timer', $dest = 'console')
    {
        static $print_count = 0;

        $print_count++;
        $now  = self::timer();
        $diff = $now - $timer;

        if (empty($label)) {
            $label = 'Timer '.$print_count;
        }

        self::write_log($dest, sprintf("%s: %0.4f sec", $label, $diff));
    }