/**
  * Transforms an entity to be stored
  *
  * @param FileInterface $file File to transform
  *
  * @return mixed Entity transformed
  */
 public function transform(FileInterface $file)
 {
     return $file->getId() . '.' . $file->getExtension();
 }
 /**
  * Transforms an entity to be stored
  *
  * @param FileInterface $file File to transform
  *
  * @return string Entity transformed
  */
 public function transform(FileInterface $file)
 {
     return $file->getPath() . DIRECTORY_SEPARATOR . $file->getId() . '.' . $file->getExtension();
 }