@Test
	public void testOneDiff() {
		B newB = new B();
		newB.id = 3;
		newB.name=targetB.name;
		final String newAddr = "here am i, alone on a hill!";
		newB.addr = newAddr;
		int expected = 2; // id and addr differ
		final List<DiffField> diffs = DiffObj.diffObj(targetB, newB);
		assertEquals(expected, diffs.size());
		// Cannot depend on order
		boolean found = false;
		for (DiffObj.DiffField d : diffs) {
			if (d.name.equals("addr") && d.newVal.equals(newAddr)) {
				found = true;
			}
		}
		assertTrue(found);
	}