Hello, may someone explain how to correct use of new aggregation protocol?

I need aggregate all routes from table all_bg and push result to all_bg_aggr, for now look like aggregation is not working. May someone explain what I do wrong?

Here is my bird.conf:

```log "/var/log/bird.log" { debug, trace, info, remote, warning, error, auth, fatal, bug };
router id 192.168.111.10;

# debug protocols all;
# debug protocols { events, states };

# watchdog warning 5 s;
# watchdog timeout 30 s;


ipv4 table all_bg_aggr;
ipv4 table all_bg;

filter NEXT_HOP_OVERRIDE {
    if ( true ) then {
        gw = 192.168.111.254;
        accept;
    }
    reject;
}


protocol device {
}

protocol direct {
    disabled;
    ipv4;
    ipv6;
}

protocol kernel {
    ipv4 {
        import none;
        export none;
    };
}

protocol static legacy_bg {
    ipv4 {
        table all_bg;
        import filter NEXT_HOP_OVERRIDE;
    };   
    include "/etc/bird/legacy.conf";
}

protocol static custom_bg {
    ipv4 {
        table all_bg;
        import filter NEXT_HOP_OVERRIDE;
    };
    include "/etc/bird/custom.conf";
}

protocol static aws_bg {
    ipv4 {
        table all_bg;
        import filter NEXT_HOP_OVERRIDE;
    };   
    include "/etc/bird/aws.conf";
}

protocol static fastly_bg {
    ipv4 {
        table all_bg;
        import filter NEXT_HOP_OVERRIDE;
    };   
    include "/etc/bird/fastly.conf";
}

protocol static cloudflare_bg {
    ipv4 {
        table all_bg;
        import filter NEXT_HOP_OVERRIDE;
    };   
    include "/etc/bird/cloudflare.conf";
}

protocol static mailru_vk_bg {
    ipv4 {
        table all_bg;
        import filter NEXT_HOP_OVERRIDE;
    };   
    include "/etc/bird/vk-mrg.conf";
}

# Get routes from Antifilter.download
protocol bgp antifilter_d_bg {
    local as 64900;
    neighbor 45.154.73.71 as 65432 external;
    multihop;
    hold time 240;
    graceful restart;
    ipv4 {
    table all_bg;
    import filter NEXT_HOP_OVERRIDE;
        export none;
    };
}

# Get routes from Antifilter.network
protocol bgp antifilter_n_bg {
    local as 64900;
    neighbor 51.75.66.20 as 65444 external;
    multihop;
    hold time 240;
    graceful restart;
    ipv4 {
    table all_bg;
    import filter NEXT_HOP_OVERRIDE;
        export none;
    };
}


# Aggregate routes
protocol aggregator all_bg_aggregator {
  table all_bg;
  peer table all_bg_aggr;
  export all;
  aggregate on net;
  merge by {
    print "Merging all these: ", routes;
    bgp_med = 0;
    for route r in routes do {
      if ! defined(r.bgp_med) then { unset(bgp_med); accept; }
      print r, " bgp_med: ", r.bgp_med;
      bgp_med = bgp_med + r.bgp_med;
      bgp_community = bgp_community.add(r.bgp_community);
    }
    accept;
  };
}


# Export routes to Cisco C8000v
protocol bgp rr_bg {
    local as 64900;
    neighbor 192.168.111.1 as 65137;
    graceful restart;
    ipv4 {
    table all_bg_aggr;
        import none;
    export all;
    };
}
```