code: def child_regions(self):
          
          start, end = self.get_range()
          block = self._trigger.next()
          ref_lvl = self.scope_level
          while block.blockNumber() <= end and block.isValid():
              lvl = TextBlockHelper.get_fold_lvl(block)
              trigger = TextBlockHelper.is_fold_trigger(block)
              if lvl == ref_lvl and trigger:
                  yield FoldScope(block)
              block = block.next()
docs: This generator generates the list of direct child regions.