anchor.diff:  %%      The key is expected to be the first element of Entry.
   -spec put(DB::db(), Entry::entry()) -> db().
   put({DB, _DBName} = State, Entry) ->
  -	ok = hanoidb:put(DB, ?IN(element(1, Entry)), ?IN(Entry)	),
  -	State.
  +    ok = hanoidb:put(DB, ?IN(element(1, Entry)), ?IN(Entry)    ),
  +    State.
   
   %% @doc Returns the entry that corresponds to Key or {} if no such tuple exists.
   -spec get(DB::db(), Key::key()) -> entry() | {}.
   get({DB, _DBName}, Key) ->
  -	case hanoidb:get(DB, ?IN(Key)) of
  -        not_found	-> {};
  -        {ok, Entry}	-> ?OUT(Entry)
  -	end.
  +    case hanoidb:get(DB, ?IN(Key)) of
  +        not_found    -> {};
  +        {ok, Entry}    -> ?OUT(Entry)
  +    end.
   
   %% @doc Deletes the tuple saved under Key and returns the new DB.
   %%      If such a tuple does not exists nothing is changed.
  
positive.code: -export_type([db/0]).
  -endif.
  
  -type hanoidb_config_option() ::	{compress, none | gzip | snappy | lz4}
  								| {page_size, pos_integer()}
  								| {read_buffer_size, pos_integer()}
  								| {write_buffer_size, pos_integer()}
  								| {merge_strategy, fast | predictable }
  								| {sync_strategy, none | sync | {seconds, pos_integer()}}
  								| {expiry_secs, non_neg_integer()}
  								| {spawn_opt, list()}.
  
  %% @doc Creates new DB handle named DBName.
  -spec new(DBName::nonempty_string()) -> db().
  new(DBName) ->
  	new_db(DBName, []). % hanoidb's default options. May need tuning.
  
  %% @doc Re-opens an existing-on-disk database.
  -spec open(DBName::nonempty_string()) -> db().
  
negative.code: %% @equiv foldr(DB, Fun, Acc0, Interval, get_load(DB))
  %% @doc   Returns a potentially larger-than-memory dataset. Use with care.
  -spec foldr(DB::db(), Fun::fun((Key::key(), AccIn::A) -> AccOut::A), Acc0::A,
              Interval::db_backend_beh:interval()) -> Acc1::A.
  foldr(State, Fun, Acc, Interval) ->
      foldr_helper(State, Fun, Acc, Interval, -1).
  
  