anchor.diff:  is_pollable({'receive', blocked}) -> true;
   is_pollable({'after', _Info}) -> true;
   is_pollable(_Else) -> false.
  +
  +update_instr_info(Lid, Selected, CommonNewTraceTop) ->
  +    IntermediateTraceTop = handle_instruction(Selected, CommonNewTraceTop),
  +    UpdatedClockVector =
  +        lookup_clock(Lid, IntermediateTraceTop#trace_state.clock_map),
  +    {Lid, RewrittenInstr, _Msgs} = IntermediateTraceTop#trace_state.last,
  +    Messages = orddict:from_list(replace_messages(Lid, UpdatedClockVector)),
  +    IntermediateTraceTop#trace_state{last = {Lid, RewrittenInstr, Messages}}.
   
   filter_awaked(SleepSet, Nexts, Selected) ->
       Filter =
  
positive.code:                 end
          end,
      dynamic_loop_acc(Fun, []).
  
negative.code:     ok;
  send_message(Lid, Message) ->
      Pid = concuerror_lid:get_pid(Lid),
      send_message(Pid, Message).
  
  %% Notify the scheduler of an event.
  %% If the calling user process has an associated LID, then send
  