anchor.diff:  
   start_demo(debug) ->
       demo([{debug, [trace]}]).
  -    
  -interval_ms() -> 60000.
   
   
   %% @spec (Connection, Queue, RpcHandler) -> RpcServer
  
positive.code: -export([start_demo/0, start_demo/1]).
  
  -record(state, {channel,
                  proxy_queue,
                  proxy_exchange,
                  rpc_exchange,
                  control_exchange,
                  correlation_id = make_ref(),
                  continuations = dict:new(),
                  stats}).
  
negative.code: 
  demo(Opts) ->
      {ok, Connection} = amqp_connection:start(network, #amqp_params{}),
      ControlExchange = <<"control">>,
      ControlRKey = <<"control.smart_proxy">>,
      Pid = amqp_smart_proxy:start([Connection, ControlExchange, ControlRKey, Opts]),
      io:format("Server started with Pid: ~p~n", [Pid]),
      Pid.
  
  