updated.setModelAId("testreference1");
updated.setModelBId("testreference2");
updated.setTest("this is a new teststring");
ModelDiff diff = ModelDiff.createModelDiff((OpenEngSBModel) old, (OpenEngSBModel) updated);
assertThat(diff.getDifferences().size(), is(1));
ModelDiffEntry entry = diff.getDifferences().values().iterator().next();
assertThat((String) entry.getBefore(), is("this is a teststring"));
assertThat((String) entry.getAfter(), is("this is a new teststring"));
}