anchor.diff:  
   -record (state, {
     seed,             % seed host
  -  host,             % local host
  -  used_ports = []   % used ports
  +  host              % local host
   }).
   
   -define(SERVER, ?MODULE).
   -define (ROUTER_SERVERS, 'ROUTER SERVERS').
   -define (NODE_SERVERS, 'NODE SERVERS').
  +-define (APP_HANDLER, app_handler).
   
   %%====================================================================
   %% API
  
positive.code:     false -> get_next_available_host()
    end.
  
  get_next_available_port(Host) ->
    rpc:call(Host, ?MODULE, get_next_available_port, []).
  
  start_new_instance(Name, Host, Port) ->
    {ok, P} = app_launcher_fsm:start_link(Name, Host, Port),
    app_launcher_fsm:launch(P).
negative.code:   
    {ok, #state{
      seed = Seed,
      host = LocalHost
    }}.
  
  %%--------------------------------------------------------------------
  