resourceValidate example

// Move the file to the correct location after validation. Use     // FileSystemInterface::EXISTS_ERROR as the file location has already been     // determined above in FileSystem::getDestinationFilename().     try {
      $this->fileSystem->move($temp_file_path, $file_uri, FileSystemInterface::EXISTS_ERROR);
    }
    catch (FileException $e) {
      throw new HttpException(500, 'Temporary file could not be moved to file location');
    }

    // Second step of the validation on the file object itself now.     $this->resourceValidate($file);

    $file->save();

    $this->lock->release($lock_id);

    // 201 Created responses return the newly created entity in the response     // body. These responses are not cacheable, so we add no cacheability     // metadata here.     return new ModifiedResourceResponse($file, 201);
  }