### Question:
ConfigUtils { public static String serialize(Config config) { return config.root().withOnlyKey("oryx").render(ConfigRenderOptions.concise()); } private  ConfigUtils(); static Config getDefault(); static Config overlayOn(Map<String,?> overlay, Config underlying); static String getOptionalString(Config config, String key); static List<String> getOptionalStringList(Config config, String key); static Double getOptionalDouble(Config config, String key); static void set(Map<String,Object> overlay, String key, Path path); static String serialize(Config config); static Config deserialize(String serialized); static String prettyPrint(Config config); static Properties keyValueToProperties(Object... keyValues);  }### Answer:
@Test public void testSerialize() { String serialized = ConfigUtils.serialize(ConfigUtils.getDefault()); assertContains(serialized, "update-class"); Config deserialized = ConfigUtils.deserialize(serialized); assertEquals( ConfigUtils.getDefault().getString("oryx.serving.api.port"), deserialized.getString("oryx.serving.api.port")); }