anchor.diff:  
   -record(state, {index               :: non_neg_integer(),
                   db                  :: eleveldb:db_ref(),
  +                start_time          :: pos_integer(),
  +                accesses            :: dict(),
                   last_save           :: float()}).
   -opaque state() :: #state{}.
   
  
positive.code:         #edis_item{key = Key, type = string, encoding = raw,
                     expire = edis_util:now() + Seconds,
                     value = Value}), []),
    {reply, Reply, State};
  handle_call({set_range, Key, Offset, Value}, _From, State) ->
    case erlang:size(Value) of
      0 ->
        {reply, {ok, 0}, State}; %% Copying redis behaviour even when documentation said different
      Length ->
        Reply =
          update(State#state.db, Key, string, raw,
                 fun(Item = #edis_item{value = <<Prefix:Offset/binary, _:Length/binary, Suffix/binary>>}) ->
                         NewV = <<Prefix/binary, Value/binary, Suffix/binary>>,
  
negative.code:                        #edis_item{key = Key, encoding = raw,
                                    type = string, value = Value})} || {Key, Value} <- KVs],
                      []),
    {reply, Reply, stamp([K || {K, _} <- KVs], State)};
  handle_call({set_nx, KVs}, _From, State) ->
    Reply =
      case lists:any(
             fun({Key, _}) ->
                     exists_item(State#state.db, Key)
             end, KVs) of
        true ->
          {reply, {error, already_exists}, State};
        false ->
          eleveldb:write(State#state.db,
                         [{put, Key,
                           erlang:term_to_binary(
                             #edis_item{key = Key, encoding = raw,
                                        type = string, value = Value})} || {Key, Value} <- KVs],
                         [])
      end,
    {reply, Reply, stamp([K || {K, _} <- KVs], State)};
  handle_call({set_bit, Key, Offset, Bit}, _From, State) ->
    Reply =
      update(State#state.db, Key, string, raw,
  