@Test
public void testGetSubConfiguration() {

  final String parentKey = "parent";
  final String childKey = "child";
  final String key = parentKey + "." + childKey;
  final String v1 = randomUUID().toString();
  final String v2 = randomUUID().toString();
  InMemoryConfiguration conf1 = new InMemoryConfiguration();
  conf1.define(key, v1);
  InMemoryConfiguration conf2 = new InMemoryConfiguration();
  conf1.define(key, v2);
  Configuration conf = HierachicalConfiguration.create(conf1, conf2);
  Configuration subConf = conf.getSubconfiguration(parentKey);
  assertEquals(v2, subConf.get(childKey));
}