code: def markLoadingStarted(self):
          
          if self.isThreadEnabled():
              XLoaderWidget.start(self)
          
          if self.showTreePopup():
              tree = self.treePopupWidget()
              tree.setCursor(Qt.WaitCursor)
              tree.clear()
              tree.setUpdatesEnabled(False)
              tree.blockSignals(True)
              
              self._baseHints = (self.hint(), tree.hint())
              tree.setHint('Loading records...')
              self.setHint('Loading records...')
          else:
              self._baseHints = (self.hint(), '')
              self.setHint('Loading records...')
          
          self.setCursor(Qt.WaitCursor)
          self.blockSignals(True)
          self.setUpdatesEnabled(False)
          
          # prepare to load
          self.clear()
          use_dummy = not self.isRequired() or self.isCheckable()
          if use_dummy:
              self.addItem('')
          
          self.loadingStarted.emit()
docs: Marks this widget as loading records.