anchor.diff:  %% ------------------------------------------------------------------
   %% Internal Function Definitions
   %% ------------------------------------------------------------------
  +
  +close_connection(undefined) ->
  +    % connection is already closed
  +    ok;
  +close_connection(Connection) ->
  +    of_driver:close_connection(Connection).
   
   signal_stop(Reason) ->
       ?INFO("ofs_handler(~p) stopping: ~p", [self(), Reason]),
  
positive.code:                           auxid = AuxId,
                            callback_state = CallbackState,
                            callback_mod = Module}) ->
      ?WARNING("OFS HANDLER connection terminate Reason : ~p",[Reason]),
      of_driver:close_connection(Connection),
      case AuxId of
          main ->
              do_callback(Module, terminate, [CallbackState]);
  
negative.code:     end,
      {reply, ok, State};
  handle_call({disconnect, Reason}, _From, State) ->
      % connection closed
      signal_stop(Reason),
      {reply, ok, State#?STATE{connection = undefined}};
  handle_call(_Request, _From, State) ->
      % unknown request
      {reply, ok, State}.
  