public Object unify(Object o, int hash, Comparator comparator) {
		// /#ifdef JDK12
		cleanUp();
		// /#endif
		int slot = Math.abs(hash % buckets.length);
		for (Bucket b = buckets[slot]; b != null; b = b.next) {
			Object old = b.get();
			if (old != null && comparator.compare(o, old) == 0)
				return old;
		}

		put(hash, o);
		return o;
	}