### Question:
Classes { public static boolean isSet(Object object) { return object != null && isSet(object.getClass()); } private  Classes(); static boolean isElement(Class<?> type); static boolean isVertex(Object object); static boolean isVertex(Class<?> type); static boolean isEdge(Object object); static boolean isEdge(Class<?> type); static boolean isList(Object object); static boolean isList(Class<?> type); static boolean isSet(Object object); static boolean isSet(Class<?> type); static boolean isCollection(Object object); static boolean isCollection(Class<?> type); static boolean isFunctional(Class<?> type); @SuppressWarnings({"PMD.ShortMethodName"}) static boolean is(Class<?> type, Object that); @SuppressWarnings({"PMD.ShortMethodName"}) static boolean is(Object object, Class<?> that); @SuppressWarnings({"PMD.ShortMethodName"}) static boolean is(Class<?> type, Class<?> that); @SuppressWarnings("unchecked") static void sortCollection(Class<?> clazz, Collection<?> collection); @SneakyThrows @SuppressWarnings("rawtypes") static Collection newCollection(Class<?> clazz); static String name(Class<?> type);  }### Answer:
@Test public void testIsSet() { assertTrue(isSet(new HashSet<>())); assertFalse(isSet(Person.class)); }