@Override
    public Set<String> getClasses() {
        return new LinkedHashSet<>(
                PreferencesFactory.get().getList("googlestorage.storage.class.options"));
    }
@Test
    public void testGetClasses() {
        assertArrayEquals(Arrays.asList(
                        "STANDARD",
                        "MULTI_REGIONAL",
                        "REGIONAL",
                        "NEARLINE",
                        "COLDLINE",
                        "ARCHIVE").toArray(),
                new GoogleStorageStorageClassFeature(session).getClasses().toArray());
    }