code: def retrieve_asset(filename):
      
  
      record = model.Image.get(asset_name=filename)
      if not record:
          raise http_error.NotFound("File not found")
      if not record.is_asset:
          raise http_error.Forbidden()
  
      return flask.send_file(record.file_path, conditional=True)
docs: Retrieves a non-image asset associated with an entry