code: def _get_parent_remote_paths(self):
          
          parent_paths = set([item.get_remote_parent_path() for item in self.file_urls])
          if '' in parent_paths:
              parent_paths.remove('')
          return parent_paths
docs: Get list of remote folders based on the list of all file urls
          :return: set([str]): set of remote folders (that contain files)