@Override
public boolean add(K k) {
if (k == null) throw new NullPointerException();
boolean retVal = !bitSet.get(k.getOrdinal());
if (retVal) {
bitSet.set(k.getOrdinal());
size++;
}
return retVal;
}
@Override
public boolean remove(Object o) {
if (o == null) return false;
K k = (K) o;
boolean retVal = bitSet.get(k.getOrdinal());
if (retVal) {
bitSet.set(k.getOrdinal(), false);
size--;
}
return retVal;
}
@Override
public boolean contains(Object o) {
K k = (K) o;
return k != null && bitSet.get(k.getOrdinal());
}