public static function toInt($size) {
    // Remove the non-unit characters from the size.
    $unit = preg_replace('/[^bkmgtpezy]/i', '', $size);
    // Remove the non-numeric characters from the size.
    $size = preg_replace('/[^0-9\.]/', '', $size);
    if ($unit) {
      // Find the position of the unit in the ordered string which is the power
      // of magnitude to multiply a kilobyte by.
      return round($size * pow(self::KILOBYTE, stripos('bkmgtpezy', $unit[0])));
    }
    else {
      return round($size);
    }
  }