engine.create(testIndex);
IndexCommit commit = mock(IndexCommit.class);
when(commit.getTimestamp()).thenReturn(new Date(42));
TestModel testModelA = new TestModel("A", 42);
TestModel testModelB = new TestModel("B", -42);
List<OpenEngSBModel> list = new ArrayList<>();
list.add((OpenEngSBModel) testModelA);
list.add((OpenEngSBModel) testModelB);
engine.execute(new InsertOperation(commit, testIndex, list));
testModelB.setTestInteger(43);
IndexCommit updateCommit = mock(IndexCommit.class);
when(updateCommit.getTimestamp()).thenReturn(new Date(84));
engine.execute(new UpdateOperation(updateCommit, testIndex, new ArrayList(Arrays.asList(testModelB))));