docs: def joiner(self):
          """
          Returns the joiner operator type for this entry widget.
          
          :return     <QueryCompound.Op>
          """
          act = self.uiJoinSBTN.currentAction()
          if not act:
              return None
          elif act.text() == 'AND':
              return QueryCompound.Op.And
          return QueryCompound.Op.Or