/** Return the first object on the free list or null if none. */
public FactoryObject getFree() {
Head head = getHead();
FactoryObject obj = head.next;
if (obj != null) {
head.next = obj.next();
obj.next(null);
}
return obj;
}
/** Add an object to the free list. */
public void setFree(FactoryObject obj) {
Head head = getHead();
obj.next(head.next);
head.next = obj;
}