docs: def _get_parent_id(self):
          """If this async is in within another async set that async id as the
          parent.
          """
          parent_id = self._options.get('parent_id')
          if parent_id:
              return parent_id
  
          from furious.context import get_current_async
  
          try:
              async = get_current_async()
          except errors.NotInContextError:
              async = None
  
          if async:
              parent_id = ":".join([async.parent_id.split(":")[0], async.id])
          else:
              parent_id = self.request_id
  
          self.update_options(parent_id=parent_id)
  
          return parent_id