public static void testCardinality() {
FixedSizeBitSet set=new FixedSizeBitSet(20);
for(int i=0; i < 20; i++)
set.set(i);
System.out.println("set = " + set);
assert set.cardinality() == 20;
}
public static void testNextClearBit() {
FixedSizeBitSet set=new FixedSizeBitSet(64);
int index=set.nextClearBit(0);