Vector merge(Vector v1, Vector v2) {
		if (v1 == null || v1.isEmpty())
			return v2;
		if (v2 == null || v2.isEmpty())
			return v1;
		Vector result = (Vector) v1.clone();
		Enumeration enum_ = v2.elements();
		while (enum_.hasMoreElements()) {
			Object elem = enum_.nextElement();
			if (!result.contains(elem))
				result.addElement(elem);
		}
		return result;
	}