code: def unfold(self):
          
          # set all direct child blocks which are not triggers to be visible
          self._trigger.setVisible(True)
          TextBlockHelper.set_collapsed(self._trigger, False)
          for block in self.blocks(ignore_blank_lines=False):
              block.setVisible(True)
              if TextBlockHelper.is_fold_trigger(block):
                  TextBlockHelper.set_collapsed(block, False)
docs: Unfolds the region.