def objects_patch(self, bucket, key, info):
    """Updates the metadata associated with an object.

    Args:
      bucket: the name of the bucket containing the object.
      key: the key of the object being updated.
      info: the metadata to update.
    Returns:
      A parsed object information dictionary.
    Raises:
      Exception if there is an error performing the operation.
    """
    url = Api._ENDPOINT + (Api._OBJECT_PATH % (bucket, Api._escape_key(key)))
    return google.datalab.utils.Http.request(url, method='PATCH', data=info,
                                             credentials=self._credentials)