private int id(ClassNode c) {
		if (c.superName == null) {
			return 1;
		} else {
			Integer i = classIds.get(new ID(c.superName));
			if (i == null) {
				i = 0;
			}
			i++;
			classIds.put(new ID(c.superName), i);
			return i;
		}
	}