def object_upload(self, bucket, key, content, content_type):
    """Writes text content to the object.

    Args:
      bucket: the name of the bucket containing the object.
      key: the key of the object to be written.
      content: the text content to be written.
      content_type: the type of text content.
    Raises:
      Exception if the object could not be written to.
    """
    args = {'uploadType': 'media', 'name': key}
    headers = {'Content-Type': content_type}

    url = Api._UPLOAD_ENDPOINT + (Api._OBJECT_PATH % (bucket, ''))
    return google.datalab.utils.Http.request(url, args=args, data=content, headers=headers,
                                             credentials=self._credentials, raw_response=True)
Writes text content to the object.

    Args:
      bucket: the name of the bucket containing the object.
      key: the key of the object to be written.
      content: the text content to be written.
      content_type: the type of text content.
    Raises:
      Exception if the object could not be written to.