MDerAttr actual = derAttrDAO.find(derivedAttribute.getId(), MDerAttr.class);
assertNotNull("expected save to work", actual);
assertEquals(derivedAttribute, actual);
MAttrValue sx = (MAttrValue) owner.getAttribute("mderived_sx").getValues().iterator().next();
MAttrValue dx = (MAttrValue) owner.getAttribute("mderived_dx").getValues().iterator().next();
assertEquals(sx.getValue() + "-" + dx.getValue(), derivedAttribute.getValue(owner.getAttributes()));
}