code: def _process_files(self, tar):
          
          # insert additional files
          for file_item in self.config.get('files', []):
              path = file_item['path']
              # remove leading slashes from path
              if path.startswith('/'):
                  path = path[1:]
              self._add_file(tar=tar,
                             name=path,
                             contents=file_item['contents'],
                             mode=file_item.get('mode', DEFAULT_FILE_MODE))
docs: Adds files specified in self.config['files'] to tarfile instance.
  
          :param tar: tarfile instance
          :returns: None