docs: def _head(self, client_kwargs):
          """
          Returns object HTTP header.
  
          Args:
              client_kwargs (dict): Client arguments.
  
          Returns:
              dict: HTTP header.
          """
          with _handle_oss_error():
              bucket = self._get_bucket(client_kwargs)
  
              # Object
              if 'key' in client_kwargs:
                  return bucket.head_object(
                      key=client_kwargs['key']).headers
  
              # Bucket
              return bucket.get_bucket_info().headers