anchor.diff:  
   -record(state, {ref :: reference(),
                   data_root :: string(),
  +                config :: config(),
                   read_opts = [],
                   write_opts = [],
  -                fold_opts = [{fill_cache, false}],
  -                write_buffer_size :: integer()}).
  +                fold_opts = [{fill_cache, false}]
  +               }).
  +
   
   -type state() :: #state{}.
   -type config() :: [{atom(), term()}].
  
positive.code: 
  %% @doc Get the status information for this eleveldb backend
  -spec status(state()) -> [{atom(), term()}].
  status(#state{data_root=DataRoot} = State) ->
      get_status(DataRoot, State).
  
  %% @doc Register an asynchronous callback
  -spec callback(reference(), any(), state()) -> {ok, state()}.
  
negative.code: %% ===================================================================
  %% Internal functions
  %% ===================================================================
  
  %% @private
  open_db(DataRoot, Config) ->
      %% Get the data root directory
      filelib:ensure_dir(filename:join(DataRoot, "dummy")),
  
      %% Use a variable write buffer size in order to reduce the number
      %% of vnodes that try to kick off compaction at the same time
      %% under heavy uniform load...
      WriteBufferMin = config_value(write_buffer_size_min, Config, 3 * 1024 * 1024),
      WriteBufferMax = config_value(write_buffer_size_max, Config, 6 * 1024 * 1024),
      random:seed(now()),
      WriteBufferSize = WriteBufferMin + random:uniform(1 + WriteBufferMax - WriteBufferMin),
  
      %% Assemble options...
      Options = [
                 {create_if_missing, true},
                 {write_buffer_size, WriteBufferSize},
                 {max_open_files, config_value(max_open_files, Config)},
                 {cache_size, config_value(cache_size, Config)},
                 {paranoid_checks, config_value(paranoid_checks, Config)}
                ],
  
      lager:debug("Opening LevelDB in ~s with options: ~p\n", [DataRoot, Options]),
      eleveldb:open(DataRoot, Options).
  
  
  %% @private
  config_value(Key, Config) ->
  