@Test
public void testGetOrDefault() {

  final Key<String> key = Key.of(randomUUID().toString(), String.class);
  final Context context = new ContextConc(root, key, randomUUID().toString());
  final Key<String> nokey = Key.of(randomUUID().toString(), String.class);
  final String expected = randomUUID().toString();
  final String actual = context.getOrDefault(nokey, expected);
  assertEquals(expected, actual);
}