src/main/java/com/googlecode/javaewah/IteratorAggregation.java
public static IteratingRLW bufferedxor(final int bufSize, final IteratingRLW... al) {
        if (al.length == 0)
            throw new IllegalArgumentException("Need at least one iterator");
        if (al.length == 1)
            return al[0];

        final LinkedList<IteratingRLW> basell = new LinkedList<IteratingRLW>();
        Collections.addAll(basell, al);

        return new BufferedIterator(new BufferedXORIterator(basell, bufSize));
    }
public static IteratingRLW bufferedxor(final int bufSize, final IteratingRLW... al) {
        if (al.length == 0)
            throw new IllegalArgumentException("Need at least one iterator");
        if (al.length == 1)
            return al[0];

        final LinkedList<IteratingRLW> basell = new LinkedList<IteratingRLW>();
        Collections.addAll(basell, al);

        return new BufferedIterator(new BufferedXORIterator(basell, bufSize));
    }
Aggregate the iterators using a bitmap buffer.

@param al      iterators to aggregate
@param bufSize size of the internal buffer used by the iterator in 64-bit words
@return xor aggregate