anchor.diff:  
   %% @doc joins two bloom filter, returned bloom filter represents their union
   -spec join(bloom_filter(), bloom_filter()) -> bloom_filter().
  +join(#bloom{size = Size, max_items = ExpItem1, items_count = Items1,
  +            filter = <<>>, hfs = Hfs},
  +     #bloom{size = Size, max_items = ExpItem2, items_count = Items2,
  +            filter = F2}) ->
  +    #bloom{size = Size, filter = F2, hfs = Hfs,
  +           max_items = erlang:max(ExpItem1, ExpItem2),
  +           items_count = Items1 + Items2 %approximation
  +           };
  +join(#bloom{size = Size, max_items = ExpItem1, items_count = Items1,
  +            filter = F1, hfs = Hfs},
  +     #bloom{size = Size, max_items = ExpItem2, items_count = Items2,
  +            filter = <<>>}) ->
  +    #bloom{size = Size, filter = F1, hfs = Hfs,
  +           max_items = erlang:max(ExpItem1, ExpItem2),
  +           items_count = Items1 + Items2 %approximation
  +           };
   join(#bloom{size = Size, max_items = ExpItem1, items_count = Items1,
               filter = F1, hfs = Hfs},
        #bloom{size = Size, max_items = ExpItem2, items_count = Items2,
  
positive.code: new_(BitSize, MaxItems, Hfs) when BitSize rem 8 =:= 0 ->
      #bloom{
             size = BitSize,
             filter = <<0:BitSize>>,
             max_items = MaxItems,
             hfs = Hfs,
             items_count = 0
  
negative.code:     PosInByte = Pos rem 8,
      PreBitsNum = Pos - PosInByte,
      AccPosBF = (2#10000000 bsr PosInByte),
      p_add_list_v2_(Rest, AccPosBF, <<0:PreBitsNum>>, BF, BFSize).
  
  p_add_list_v2_([Pos | Rest], AccPosBF, AccBF, BF, BFSize) when Pos - erlang:bit_size(AccBF) < 8 ->
      % Pos in same byte
      PosInByte = Pos rem 8,
      AccPosBF2 = AccPosBF bor (2#10000000 bsr PosInByte),
      p_add_list_v2_(Rest, AccPosBF2, AccBF, BF, BFSize);
  p_add_list_v2_([Pos | Rest], AccPosBF, AccBF, BF, BFSize) ->
      PosInByte = Pos rem 8,
      PreBitsNum2 = Pos - PosInByte,
      DiffBits = PreBitsNum2 - erlang:bit_size(AccBF) - 8,
  