anchor.diff:      case decode_integer(Bin, 7) of
           {error, Why} ->
               {error, Why};
  -        {Len, Rest} ->
  +        {ok, {Len, Rest}} ->
               case Len > size(Rest) of
                   true ->
                       {error, tooshortinput};
  
positive.code:     G = N band K,
      case G =/= K of
          true ->
              {G, Rest};
          false ->
              decode_integer_acc(Rest, Prefix, 0, K)
      end.
  
negative.code:     Acc2 = Acc + (M bsl Shift),
      case (N band 16#80) =:= 0 of
          true ->
              {ok, {Acc2, Rest}};
          false ->
              decode_integer_acc(Rest, Prefix, Shift + 7, Acc2)
      end;
  