### Question:
CategoryKnowledgeFactory { public static CategoryKnowledge getCategoryKnowledge(EntityCategory category) { return s_knowledge.get(category.getEntityClass()); }  static CategoryKnowledge getCategoryKnowledge(EntityCategory category); static CategoryKnowledge getCategoryKnowledge(Class<? extends Entity> entityClass);  }### Answer:
@Test public void testFactoryKnowsAllCategories() { for (EntityCategory cat : d_domain.getCategories()) { assertNotNull(CategoryKnowledgeFactory.getCategoryKnowledge(cat)); } }