@Override
  public <T> T unwrap(Class<T> clazz) {
    if (!clazz.isInstance(this)) {
      throw new IllegalArgumentException("Class " + clazz + " is unknown to this implementation");
    }
    @SuppressWarnings("unchecked")
    T castedEntry = (T) this;
    return castedEntry;
  }
@Test
  public void unwrap() {
    assertThat(event.unwrap(Cache.Entry.class)).isSameInstanceAs(event);
  }