anchor.diff:      DeltaRBR =
           lists:foldl(
             fun(X, AccData) ->
  -                  DB = get_prbr_state(State, X),
  +                  DB = get(State, X),
                     Delta = db_prbr:get_changes(DB, MovingInterval),
                     [{X, Delta} | AccData]
             end,
             [],
  -          [kv,
  -           txid_1, txid_2, txid_3, txid_4,
  -           leases_1, leases_2, leases_3, leases_4]
  +          get_prbr_selectors()
            ),
   
       %% db
  
positive.code:                 db_range   = []   :: [{intervals:interval(), slide_op:id()}],
                  monitor_proc            = ?required(state, monitor_proc) :: pid(),
                  prbr_kv_db = ?required(state, prbr_kv_db) :: prbr:state(),
                  txid_db1 = ?required(state, txid_db1) :: prbr:state(),
                  txid_db2 = ?required(state, txid_db2) :: prbr:state(),
                  txid_db3 = ?required(state, txid_db3) :: prbr:state(),
                  txid_db4 = ?required(state, txid_db4) :: prbr:state(),
                  lease_db1 = ?required(state, lease_db1) :: prbr:state(),
                  lease_db2 = ?required(state, lease_db2) :: prbr:state(),
                  lease_db3 = ?required(state, lease_db3) :: prbr:state(),
                  lease_db4 = ?required(state, lease_db4) :: prbr:state(),
                  lease_list = ?required(state, lease_list) :: lease_list:lease_list(),
                  snapshot_state   = null :: snapshot_state:snapshot_state() | null,
                  mr_state   = ?required(state, mr_state)  :: orddict:orddict(),
  
negative.code:     {T1State, MoveRBRData} =
          lists:foldl(
            fun(X, {AccState, AccData}) ->
                    Old = get(State, X),
                    MoveData = db_prbr:get_entries(Old, MovingInterval),
                    New = db_prbr:record_changes(Old, MovingInterval),
                    {set_prbr_state(AccState, X, New), [{X, MoveData} | AccData]}
            end,
            {State, []},
            get_prbr_selectors()
           ),
  
      %% snapshot state and db
  