code: def Decode(self, encoded_data):
      
      try:
        decoded_data = base64.b32decode(encoded_data, casefold=False)
      except (TypeError, binascii.Error) as exception:
        raise errors.BackEndError(
            'Unable to decode base32 stream with error: {0!s}.'.format(
                exception))
  
      return decoded_data, b''
docs: Decode the encoded data.
  
      Args:
        encoded_data (byte): encoded data.
  
      Returns:
        tuple(bytes, bytes): decoded data and remaining encoded data.
  
      Raises:
        BackEndError: if the base32 stream cannot be decoded.