anchor.diff:  -record(test_state, {known_vips = sets:new()}).
   
   stop() ->
  -  gen_server:call(?MODULE, clear).
  +  gen_server:call(?MODULE, clear),
  +  gen_server:stop(?MODULE).
   
   proper_test() ->
     [] = proper:module(?MODULE).
  
positive.code: 
  get_ewma_or_default({IP, Port}) ->
    case ets:lookup(connection_ewma, {IP, Port}) of
      [{_Addr, ExistingBackend}] ->
        ExistingBackend;
      _ ->
        #backend{ip_port = {IP, Port}}
    end.
  
  
negative.code:   random:seed(erlang:phash2([node()]),
                erlang:monotonic_time(),
                erlang:unique_integer()),
    connection_ewma = ets:new(connection_ewma, [{keypos, #backend.ip_port}, named_table]),
    {ok, #state{}}.
  
  %%--------------------------------------------------------------------
  