code: def set_attribute(self, app, key, value):
          
          path = 'setattribute/' + parse.quote(app, '') + '/' + parse.quote(
              self._encode_string(key), '')
          res = self._make_ocs_request(
              'POST',
              self.OCS_SERVICE_PRIVATEDATA,
              path,
              data={'value': self._encode_string(value)}
          )
          if res.status_code == 200:
              tree = ET.fromstring(res.content)
              self._check_ocs_status(tree)
              return True
          raise HTTPResponseError(res)
docs: Sets an application attribute
  
          :param app: application id
          :param key: key of the attribute to set
          :param value: value to set
          :returns: True if the operation succeeded, False otherwise
          :raises: HTTPResponseError in case an HTTP error status was returned