iter(a2,b2);
OpenBitSet a_and = (OpenBitSet) bs1.clone(); a_and.and(bs2);
OpenBitSet a_or = (OpenBitSet) bs1.clone(); a_or.or(bs2);
// OpenBitSet a_xor = (OpenBitSet)bs1.clone(); a_xor.xor(bs2);
OpenBitSet a_andn = (OpenBitSet) bs1.clone(); a_andn.andNot(bs2);
checkEqual(a_and, b1.intersection(b2));
checkEqual(a_or, b1.union(b2));
checkEqual(a_andn, b1.andNot(b2));