### Question:
Rules implements Iterable<Rule> { public boolean isEmpty() { return rules.isEmpty(); } Rules(Set<Rule> rules);  Rules(Rule... rules);  Rules(Object... rules); void register(Object... rules); void unregister(Object... rules); void unregister(final String ruleName); boolean isEmpty(); void clear(); int size(); @Override Iterator<Rule> iterator();  }### Answer:
@Test public void isEmpty() { assertThat(rules.isEmpty()).isTrue(); }