    void _process(
      const list<PG *> &pgs,
      ThreadPool::TPHandle &handle) override {
      assert(!pgs.empty());
      osd->process_peering_events(pgs, handle);
      for (list<PG *>::const_iterator i = pgs.begin();
	   i != pgs.end();
	   ++i) {
	(*i)->put("PeeringWQ");
      }
    }
    void _process(
      const list<PG *> &pgs,
      ThreadPool::TPHandle &handle) override {
      assert(!pgs.empty());
      osd->process_peering_events(pgs, handle);
      for (list<PG *>::const_iterator i = pgs.begin();
	   i != pgs.end();
	   ++i) {
	(*i)->put("PeeringWQ");
      }
    }