anchor.diff:         is_function(Fun, 1) ->
       gen_fsm:send_event(Buffer, {set_active, TargBytes, Fun}).
   
  +resize_msg_buffer(Buffer, NewSize)
  +  when is_integer(NewSize), NewSize > 0 ->
  +    gen_fsm:sync_send_all_state_event(Buffer, {resize_msg_buffer, NewSize}).
  +
   %% ------------------------------------------------------------------
   %% Hand crafted API for humans.
   %% ------------------------------------------------------------------
  
positive.code:     {next_state, StateName, State}.
  
  %% @private
  handle_sync_event(Event, _From, StateName, State) ->
      ?WARN("[state ~p] Unexpected event ~p",
            [StateName, Event]),
  
negative.code:          ,start_link/4
           ,set_active/3
           ,notify/1
           ,resize_msg_buffer/2
          ]).
  
  -export([active/2,
  