code: def set_files(self, files_downloaded, files_failed):
          
          self.files_downloaded = files_downloaded
          self.files_failed = files_failed
          self.__record_progress(Status.GET_FILE_DIFF)
docs: set_files: records progress from downloading files
              Args:
                  files_downloaded ([str]): list of files that have been downloaded
                  files_failed ([str]): list of files that failed to download
              Returns: None