anchor.diff:      %% process hold back messages for tx_state
       %% @TODO better use a foldr
       %% io:format("Starting hold back queue processing~n"),
  -    _ = [ on(OldMsg, State) || OldMsg <- lists:reverse(tx_state:get_hold_back(NewEntry)) ],
  +    _ = [ on(OldMsg, NewState) || OldMsg <- lists:reverse(tx_state:get_hold_back(NewEntry)) ],
       %% process hold back messages for tx_items
  -    _ = [ [ on(OldMsg, State)
  +    _ = [ [ on(OldMsg, NewState)
           || OldMsg <- lists:reverse(tx_item_state:get_hold_back(Item)) ]
         || Item <- NewItemStates],
       %% io:format("Stopping hold back queue processing~n"),
  
positive.code: state_get_lacceptor(State)     -> element(4, State).
  -spec state_get_gllearner(state() | state_uninit()) -> comm:mypid().
  state_get_gllearner(State) -> element(5, State).
  % -spec state_get_subs(state() | state_uninit()) ->
  %                             [{comm:mypid(), non_neg_integer()}].
  % state_get_subs(State)          -> element(6, State).
  -spec state_get_qmsg(state_uninit()) -> msg_queue:msg_queue().
  state_get_qmsg(State)          -> element(7, State).
  -spec state_set_qmsg(state_uninit(), msg_queue:msg_queue()) -> state_uninit().
  
negative.code:             %% In the future, we will handle this using msg_delay for
              %% outstanding txids to trigger a delete of the items.
      end,
      NewState;
  
  %% generated by on(register_TP) via msg_delay to not increase memory
  %% footprint
  