#fixed code
                                @Override
    public ValueBlock filter(PositionBlock positions)
    {
        return MaskedValueBlock.maskBlock(this, positions);
    }
#vulnerable code 
                                @Override
    public ValueBlock filter(PositionBlock positions)
    {
        // find selected positions
        Set<Integer> indexes = new HashSet<>();
        for (long position : positions.getPositions()) {
            if (range.contains(position)) {
                indexes.add((int) (position - range.lowerEndpoint()));
            }
        }

        // if no positions are selected, we are done
        if (indexes.isEmpty()) {
            return EmptyValueBlock.INSTANCE;
        }


        // build a buffer containing only the tuples from the selected positions
        DynamicSliceOutput sliceOutput = new DynamicSliceOutput(1024);

        int currentOffset = 0;
        for (int index = 0; index < getCount(); ++index) {
            Slice currentPositionToEnd = slice.slice(currentOffset, slice.length() - currentOffset);
            int size = tupleInfo.size(currentPositionToEnd);

            // only write selected tuples
            if (indexes.contains(index)) {
                sliceOutput.writeBytes(slice, currentOffset, size);
            }

            currentOffset += size;
        }

        // todo what is the start position
        return new UncompressedValueBlock(Ranges.closed(0L, (long) indexes.size() - 1), tupleInfo, sliceOutput.slice());
    } 
                            #location 35 
                            #vulnerability type RESOURCE_LEAK