anchor.diff:  
   -include("basho_bench.hrl").
   
  --record(basho_bench_config_state, {config_keys}).
  +-record(basho_bench_config_state, {}).
   
   -type state() :: #basho_bench_config_state{}.
   %% ===================================================================
   %% Public API
   %% ===================================================================
   
  +%% Todo: ensure_started before calling on any gen_server APIs.
   ensure_started() -> 
       start_link().
   
  
positive.code: 
  -spec init(term()) -> {ok, state()}.  
  init(_Args) ->
      State = #basho_bench_config_state{config_keys = base_config()},
      {ok, State}.
  
  -spec code_change(term(), state(), term()) -> {ok, state()}.
  
negative.code:     case gen_server:call({global, ?MODULE}, {get, Key}) of
          {ok, Value} ->
              Value;
          undefined ->
              erlang:error("Missing configuration key", [Key])
      end.
  
  