@Test
public void testAccept() {

  String propertyId = PropertyHelper.getPropertyId("category1", "foo");
  TestCategoryPredicate predicate = new TestCategoryPredicate(propertyId);
  TestPredicateVisitor visitor = new TestPredicateVisitor();
  predicate.accept(visitor);
  Assert.assertSame(predicate, visitor.visitedCategoryPredicate);
}