code: def _update_data(self):
          
          _old = self.folds
          self.folds = _get_fold_levels(self.editor)
  
          # only update our dropdown lists if the folds have changed.
          if self.folds != _old:
              self.classes, self.funcs = _split_classes_and_methods(self.folds)
              self.populate_dropdowns()
docs: Update the internal data values.