@Test
public void testPut() {

  // given
  final Context expected = EmptyContext.getInstance()
      .withValue(Key.of(randomUUID().toString(), String.class), randomUUID().toString())
      .withValue(Key.of(randomUUID().toString(), String.class), randomUUID().toString())
      .withValue(Key.of(randomUUID().toString(), String.class), randomUUID().toString());
  final ContextStorage<Context> contextStorage = new UnmodifiableContextStorage(expected);
  // then
  final Context actual = contextStorage.get();
  assertEquals(expected, actual);
}