code: def _propagate_up(self, handle, target_id, name=None):
          
          if self.parent:
              stream = self.router.stream_by_id(self.parent.context_id)
              self._send_one(stream, handle, target_id, name)
docs: In a non-master context, propagate an update towards the master.
  
          :param int handle:
              :data:`mitogen.core.ADD_ROUTE` or :data:`mitogen.core.DEL_ROUTE`
          :param int target_id:
              ID of the connecting or disconnecting context.
          :param str name:
              For :data:`mitogen.core.ADD_ROUTE`, the name of the new context
              assigned by its parent. This is used by parents to assign the
              :attr:`mitogen.core.Context.name` attribute.