anchor.diff:              _ ->
                   Acc
           end
  -    end,
  -    _List = leo_backend_db_api:fetch(State, TargetPrefix, Fun),
  -%%%    io:format(user, "[debug]prefix 1: list:~p~n", [List]),
  -    {ok, State}.
  +    end.
   
  -%% ${integer}_
   gen_prefix() ->
       NumOfPrefix = basho_bench_config:get(num_of_prefix, 1000),
       IntPrefix = random:uniform(NumOfPrefix),
  
positive.code: 
  run(prefix_get, _KeyGen, _ValueGen, State) ->
      TargetPrefix = gen_prefix(),
      Fun = fun(K, _V, Acc) ->
          [PrefixBin|_]= binary:split(K, <<$:>>),
          case PrefixBin of
              TargetPrefix ->
  
negative.code:     random:seed(),
      Ret = leo_backend_db_api:status(InstanceName),
      io:format(user, "[start]status:~p~n", [Ret]),
      erlang:put(worker_id, 1),
      {ok, InstanceName};
  new(_) ->
      InstanceName = basho_bench_config:get(instance_name, 'test_backend_db'),
  