anchor.diff:      G = N band K,
       case G =/= K of
           true ->
  -            {G, Rest};
  +            {ok, {G, Rest}};
           false ->
               decode_integer_acc(Rest, Prefix, 0, K)
       end.
  
positive.code:     case decode_integer(Bin, Prefix) of
          {error, Why} ->
              {error, Why};
          {Index, Rest} ->
              case header:get(Index, Context) of
                  error ->
                      {error, outofindex};
  
negative.code: 
  test_int() ->
      Bin1337 = encode_integer(1337, 5, 0),
      {ok, {1337, <<>>}} = decode_integer(Bin1337, 5),
      Bin42 = encode_integer(42, 8, 0),
      {ok, {42, <<>>}} = decode_integer(Bin42, 8),
      BinInt64Max = encode_integer(1 bsl 64, 7, 128),
      {ok, {1 bsl 64, <<"garbage">>}} =
          decode_integer(<<BinInt64Max/binary, "garbage">>, 7).
  
  test_encode() ->
  