### Question:
Fields { public static String propertyKey(Field field) { String key = alias(field, Alias::key); return key != null ? key : field.getName(); } private  Fields(); static boolean has(Field field, Class<? extends Annotation> annotationType); static String alias(AnnotatedElement element, Function<Alias, String> property); static String propertyKey(Field field); @SneakyThrows static Object propertyValue(Field field, Object instance); static Field field(E element, String fieldName); static Field field(Class<E> elementType, String fieldName); static List<Field> fields(E element); static List<Field> fields(E element, Predicate<Field> predicate); static List<Field> fields(Class<E> elementType); static List<Field> fields(Class<E> elementType,
      Predicate<Field> predicate); static Class<?> listType(Field field); static boolean isSimple(Field field); static long elementCacheSize; static final Comparator<Field> BY_NAME; static final Comparator<Field> BY_KEYS; }### Answer:
@Test public void testPropertyKey() { assertEquals("name", propertyKey(name)); }