anchor.diff:  
   handle_call({lookup, Id}, From, State) ->
   	{Pid, Npcs} = State,
  -	MyBucket = <<"npc">>,
   	BinId = erlang:term_to_binary(Id),
  -	{ok, Fetched1} = riakc_pb_socket:get(Pid, MyBucket, BinId),
  +	{ok, Fetched1} = riakc_pb_socket:get(Pid, ?MyBucket, BinId),
   	Val1 = binary_to_term(riakc_obj:get_value(Fetched1)),
   	{reply, {ok, Val1}, State};
   
  
positive.code: 
  handle_call({add, auto_increment}, From, State) ->
  	{Pid, Npcs} = State,
  	MyBucket = <<"npc">>,
  	Id = rutil:auto_increment("npc"),
  	BinId = erlang:term_to_binary(Id),
  	Obj1 = riakc_obj:new(MyBucket, BinId, "default"),
  	riakc_pb_socket:put(Pid, Obj1),
  	NewState = {Pid, [Id | Npcs]},
  	{reply, {ok, Id}, NewState};
  
  handle_call({add, Id}, From, State) ->
  	{Pid, Npcs} = State,
  	MyBucket = <<"npc">>,
  	BinId = erlang:term_to_binary(Id),
  	{ok, Fetched} = riakc_pb_socket:get(Pid, MyBucket, BinId),	%% check if key existing "BinId"
  	NewState = {Pid, [Id | Npcs]},
  	{reply, ok, NewState};
  
  
negative.code: -export([remove/1]).
  -export([run/0]).
  -export([run/1]).
  
  -define(MyBucket, <<"npc">>).
  
  %%
  %% APIs
  