anchor.diff:  %% @end
   %%--------------------------------------------------------------------
   handle_cast(prepare, State) ->
  +    % TODO: sanitize hostname
  +    {ok, Hostname} = inet:gethostname(),
  +    HostnameBS = list_to_binary(Hostname),
  +    Path = <<"statser.instrumentation.", HostnameBS/binary, ".">>,
  +
       % TODO: determine interval from configuration
       Interval = 60 * 1000,
   
       lager:info("preparing instrumentation service timer with interval of ~w ms", [Interval]),
   
       {ok, Timer} = timer:send_interval(Interval, update_metrics),
  -    {noreply, State#state{timer=Timer}};
  +    {noreply, State#state{path=Path, timer=Timer}};
   
   handle_cast({increment, Key, Amount}, State) ->
       Map = increment_metrics(Key, Amount, State#state.metrics),
  
positive.code: %% @end
  %%--------------------------------------------------------------------
  handle_info(update_metrics, State) ->
      Metrics = State#state.metrics,
      lager:debug("instrumentation: handle metrics update - current ~p", [Metrics]),
  
      {noreply, State};
  
  
negative.code: %%%===================================================================
  %%% Internal functions
  %%%===================================================================
  
  publish(Key, Value, TS, Path) ->
      Metric = <<Path/binary, Key/binary>>,
      gen_server:cast(statser_router, {line, Metric, Value, TS}).
  
  
  increment_metrics(Key, Amount, Map) when is_number(Amount) ->
      Update = fun(Value) when is_number(Value) -> Value + Amount;
  