anchor.diff:  -spec bp_barrier(pid()) -> ok.
   bp_barrier(Pid) ->
       Pid ! {'$gen_component', bp, barrier},
  +    ok.
  +
  +-spec bp_barrier_release(pid()) -> ok.
  +bp_barrier_release(Pid) ->
  +    Pid ! {'$gen_component', bp, barrier_release},
       ok.
   
   %% @doc Brings the given gen_component into a state that is paused in
  
positive.code: on_gc_msg({'$gen_component', bp, barrier} = Msg, UState, GCState) ->
      NewGCState = gc_bp_hold_back(GCState, Msg),
      loop(UState, NewGCState);
  on_gc_msg({'$gen_component', bp, breakpoint, step, _Stepper} = Msg,
            UState, GCState) ->
      NewGCState = gc_bp_hold_back(GCState, Msg),
  
negative.code:     wait_for_bp_leave(Msg, State, true);
  on_bp_req_in_bp(Msg, State,
                  {'$gen_component', bp, barrier}, _IsFromQueue) ->
      %% we are in breakpoint. Consume this bp message
      wait_for_bp_leave(Msg, State, true);
  on_bp_req_in_bp(Msg, State,
                  {'$gen_component', bp, barrier_release}, _IsFromQueue) ->
      %% we are in breakpoint. Consume this bp message
      wait_for_bp_leave(Msg, State, true);
  on_bp_req_in_bp(Msg, State,
  