code: def _fields(self):
          
          return (
              ('reference_name', self.reference_name,),
              ('annotation_name', self.annotation_name),
              ('annotation_version', self.annotation_version),
              ('cache_directory_path', self.cache_directory_path),
              ('decompress_on_download', self.decompress_on_download),
              ('copy_local_files_to_cache', self.copy_local_files_to_cache)
          )
docs: Fields used for hashing, string representation, equality comparison