@Test
public void toStringSerializable() throws Exception {

	Serializable obj = new Integer(4);
	String b64;
	try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
		try (ObjectOutputStream oos = new ObjectOutputStream(baos)) {
			oos.writeObject(obj);
		}
		b64 = Base64.getEncoder().encodeToString(baos.toByteArray());
	}
	assertEquals(b64, XMLUtil.toString(obj));
}