anchor.diff:  
   add_endpoints(Config) ->
       Pid = ?config(balancer, Config),
  -    ?assert(meck:called(myxi_topology, add_endpoints, [[]], Pid)).
  +    Args = ?config(endpoints, Config),
  +    ?assert(meck:called(myxi_topology, add_endpoints, [Args], Pid)).
   
   register_balancer(_Config) ->
       ?assert(is_pid(whereis(?BALANCER))).
   
  -%%
  -%% Behaviour
  -%%
  +endpoints_up(Config) ->
  +    [?assertEqual({ok, {A, []}}, myxi_balancer:next(?BALANCER)) ||
  +        A <- ?config(endpoints, Config)].
   
  -next([H|T]) -> {H, T ++ [H]}.
  +endpoints_down(Config) ->
  +    meck:expect(net_adm, ping, 1, pang),
  +    ?BALANCER ! ?UP,
  +    erlang:bump_reductions(2000),
  +    [?assertEqual({error, down}, myxi_balancer:next(?BALANCER)) ||
  +        _A <- ?config(endpoints, Config)].
   
   %%
   %% Helpers
  
positive.code: 
  clear([], Config)    -> Config;
  clear([H|T], Config) -> clear(T, lists:keydelete(H, 1, Config)).
  
negative.code: -include("myxi_common_test.hrl").
  
  -define(BALANCER, myxi_dummy_balancer).
  -define(UP,       check_up).
  -define(DOWN,     check_down).
  
  %%
  %% Callbacks
  