### Question:
BasicRuleSet implements RuleSet { @Override public List<Rule> getRules() { return Collections.unmodifiableList(rules); } BasicRuleSet(Rule... rules); void addRule(Rule rule); BasicRuleSet withRule(Rule rule); @Override List<Rule> getRules(); @Override Violations applyTo(HtmlPage htmlPage); @Override String toString();  }### Answer:
@Test public void listOfRulesShouldNeverReturnNull() throws Exception { assertNotNull(ruleSet.getRules()); }