anchor.diff:      Suback = packet:gen_suback(53, 0),
       Publish = packet:gen_publish("subpub/qos0", 0, <<"message">>, []),
       {ok, Socket} = packet:do_client_connect(Connect, Connack, []),
  -    enable_on_subscribe(),
       enable_on_publish(),
       ok = gen_tcp:send(Socket, Subscribe),
       ok = packet:expect_packet(Socket, "suback", Suback),
       ok = gen_tcp:send(Socket, Publish),
       ok = packet:expect_packet(Socket, "publish", Publish),
  -    disable_on_subscribe(),
       disable_on_publish(),
       ok = gen_tcp:close(Socket).
   
  
positive.code: 
  init_per_testcase(_Case, Config) ->
      vmq_test_utils:setup(),
      vmq_server_cmd:set_config(allow_anonymous, true),
      vmq_server_cmd:set_config(retry_interval, 10),
      vmq_server_cmd:listener_start(1888, []),
      Config.
  
  end_per_testcase(_, Config) ->
      vmq_test_utils:teardown(),
      Config.
  
  
negative.code:     Subscribe = packet:gen_subscribe(79, "qos1/test", 1),
      Suback = packet:gen_suback(79, 1),
      {ok, Socket} = packet:do_client_connect(Connect, Connack, []),
      ok = gen_tcp:send(Socket, Subscribe),
      ok = packet:expect_packet(Socket, "suback", Suback),
      ok = gen_tcp:close(Socket).
  
  