code: def disable_restricted(self, ):
          
          todisable = [(self.reftrack.duplicate, self.duplicate_tb),
                       (self.reftrack.delete, self.delete_tb),
                       (self.reftrack.reference, self.reference_tb),
                       (self.reftrack.replace, self.replace_tb),]
          for action, btn in todisable:
              res = self.reftrack.is_restricted(action)
              btn.setDisabled(res)
docs: Disable the restricted buttons
  
          :returns: None
          :rtype: None
          :raises: None