anchor.diff:  export_service(Service, ServiceName) ->
       gen_server:call(?SERVER, {export_service, Service, ServiceName}).
   
  +unexport_service(Service, ServiceName) ->
  +    gen_server:call(?SERVER, {unexport_service, Service, ServiceName}).
  +
   set_service_reg(ServiceReg) ->
       gen_server:cast(?SERVER, {set_service_reg, ServiceReg}).
   
  
positive.code: 	    {reply, {ok, Bus}, State#state{busses=Busses1}}
      end;
  
  handle_call({export_service, Service, ServiceName}, _From, State) ->
      Busses = State#state.busses,
  %%     if
  %% 	Busses == [] ->
  %% 	    throw(no_bus);
  %% 	true ->
  %% 	    ignore
  %%     end,
      Fun = fun({_, Bus}) ->
  		  io:format("export_service bus ~p~n", [Bus]),
  		  ok = bus:export_service(Bus, Service, ServiceName)
  	  end,
      io:format("export_service name ~p~n", [ServiceName]),
      lists:foreach(Fun, Busses),
      {reply, ok, State};
  
  
negative.code: 	 start_link/0,
  	 get_bus/2,
  	 export_service/2,
  	 unexport_service/2,
  	 set_service_reg/1
  	]).
  
  