anchor.diff:  
   handle_info(flush, #state{instance_name=InstanceName, conn=Conn}=State) ->
       Stats = ets:tab2list(?MODULE),
  -    [ets:update_counter(?MODULE, Key, -1 * Val) || {Key, Val} <- Stats],
  +    [ets:update_counter(?MODULE, Key, -1 * Val)
  +     || {Key, Val} <- Stats,
  +        lists:member(Key, keys())],
       HerokuDomain = heroku_domain(),
       spawn(fun() ->
           Stats1 = [{instance_name, list_to_binary(InstanceName)},
                     {branch, git_branch()},
  -                  {'AZ', availability_zone()},
  -                  proplists:lookup(message_received, Stats),
  -                  proplists:lookup(message_processed, Stats),
  -                  proplists:lookup(message_routed, Stats),
  -                  proplists:lookup(message_dropped, Stats),
  -                  proplists:lookup(work_queue_dropped, Stats),
  -                  proplists:lookup(drain_buffer_dropped, Stats),
  -                  proplists:lookup(redis_buffer_dropped, Stats)],
  +                  {'AZ', availability_zone()} |
  +                   [ proplists:lookup(K, Stats)
  +                     || K <- keys() ]],
           Json = iolist_to_binary(mochijson2:encode({struct, Stats1})),
           redo:cmd(Conn, [<<"PUBLISH">>, iolist_to_binary([HerokuDomain, <<":stats">>]), Json], 60000)
       end),
  
positive.code: incr("redis_buffer_dropped", Inc) when is_integer(Inc) ->
      incr(redis_buffer_dropped, Inc);
  
  incr(Key, Inc) when is_integer(Inc) ->
      ets:update_counter(?MODULE, Key, Inc).
  
  
  %%====================================================================
  %% gen_server callbacks
  %%====================================================================
  init([Opts]) ->
      ets:new(?MODULE, [named_table, set, public]),
      ets:insert(?MODULE, [{message_received, 0},
                          {message_processed, 0},
                          {message_routed, 0},
                          {message_dropped, 0},
                          {work_queue_dropped, 0},
                          {drain_buffer_dropped, 0},
                          {redis_buffer_dropped, 0}]),
      timer:send_interval(timer:seconds(1), flush),
      case redo:start_link(undefined, Opts) of
          {ok, Conn} ->
  
negative.code: incr(Key) ->
      incr(Key, 1).
  
  -spec incr(string() | key(), integer()) -> any().
  incr("work_queue_dropped", Inc) when is_integer(Inc) ->
      incr(work_queue_dropped, Inc);
  
  