anchor.diff:                     VBucket:16, _BodyLen:32, Opaque:32, _CAS:64, _EnginePriv:16,
                      _Flags:16, _TTL:8, _Res1:8, _Res2:8, _Res3:8, Rest/binary>> =
                        Packet,
  -                 #state{downstream=Downstream, vbuckets=VBuckets,
  +                 #state{downstream=Downstream,
                           vb_filter_change_state = VBFilterChangeState} = State) ->
       case Opcode of
           ?TAP_OPAQUE ->
  
positive.code:                     _ ->
                          State
                  end,
              State2 =
                  case sets:is_element(VBucket, VBuckets) of
                      true ->
                          ok = prim_inet:send(Downstream, Packet),
                          State1#state{last_sent_seqno = Opaque};
                      false ->
                          %% Filter it out and count it
                          State1#state{bad_vbucket_count =
                                           State1#state.bad_vbucket_count + 1}
                  end,
              {ok, State2}
      end.
  
  
negative.code: 
  -type vb_filter_change_state() :: not_started | started | completed.
  
  -record(state, {upstream :: port(),
                  upstream_aux :: port(),
                  downstream :: port(),
                  downstream_aux :: port(),
  