code: def download_as_string(self, client=None, start=None, end=None):
          
          string_buffer = BytesIO()
          self.download_to_file(string_buffer, client=client, start=start, end=end)
          return string_buffer.getvalue()
docs: Download the contents of this blob as a string.
  
          If :attr:`user_project` is set on the bucket, bills the API request
          to that project.
  
          :type client: :class:`~google.cloud.storage.client.Client` or
                        ``NoneType``
          :param client: Optional. The client to use.  If not passed, falls back
                         to the ``client`` stored on the blob's bucket.
  
          :type start: int
          :param start: Optional, the first byte in a range to be downloaded.
  
          :type end: int
          :param end: Optional, The last byte in a range to be downloaded.
  
          :rtype: bytes
          :returns: The data stored in this blob.
          :raises: :class:`google.cloud.exceptions.NotFound`