setSecurityRename example

$file->setOriginalId($existingFile->id());
      }
    }

    $result = (new FileUploadResult())
      ->setOriginalFilename($originalName)
      ->setSanitizedFilename($filename)
      ->setFile($file);

    // If the filename has been modified, let the user know.     if ($event->isSecurityRename()) {
      $result->setSecurityRename();
    }

    // Set the permissions on the new file.     $this->fileSystem->chmod($file->getFileUri());

    // We can now validate the file object itself before it's saved.     $violations = $file->validate();
    foreach ($violations as $violation) {
      $errors[] = $violation->getMessage();
    }
    if (!empty($errors)) {
      

if ($munge_everything) {
        $filename .= '_';
      }
      elseif (!empty($extensions) && !in_array(strtolower($filename_part), $extensions) && preg_match("/^[a-zA-Z]{2,5}\d?$/", $filename_part)) {
        $filename .= '_';
      }
    }
    if ($final_extension !== '') {
      $filename .= '.' . $final_extension;
    }
    if ($filename !== $event->getFilename()) {
      $event->setFilename($filename)->setSecurityRename();
    }
  }

}