code: def query_int_attribute(self, target, display_mask, attr):
      
      reply = NVCtrlQueryAttributeReplyRequest(display=self.display,
                                               opcode=self.display.get_extension_major(extname),
                                               target_id=target.id(),
                                               target_type=target.type(),
                                               display_mask=display_mask,
                                               attr=attr)
      if not reply._data.get('flags'):
          return None
      return int(reply._data.get('value'))
docs: Return the value of an integer attribute