    @Test
    public void testEmptySource() throws Exception {

        final String emptySource =
                "{\"app_version\":\"0.11.6\",\"app_version_int\": 47,\"subscriptions\":[]}";

        final List<SubscriptionItem> items = ImportExportJsonHelper.readFrom(
                new ByteArrayInputStream(emptySource.getBytes(StandardCharsets.UTF_8)), null);
        assertTrue(items.isEmpty());
    }