/**
  * @param string $importDateModified
  * @param UniversalTimestamp $entryDateModified
  * @return boolean
  */
 private static function differentModTime($importDateModified, $entryDateModified)
 {
     $dateModified = UniversalTimestamp::fromWhatever($importDateModified);
     return $dateModified->asMilliseconds() != $entryDateModified->asMilliseconds();
 }
 /**
  * @param UniversalTimestamp $model
  * @return UTCDateTime;
  */
 public function encodeUniversalTimestamp($model)
 {
     return new UTCDateTime($model->asMilliseconds());
 }