}

  private abstract static class AbstractGenericDefaultValueChecker<T> extends DefaultValueChecker {

    @SuppressWarnings("unused") // called by NullPointerTester
    @Keep
    public void checkGeneric(T value, String s) {
      calledWith(value, s);
    }
  }

  private static class GenericDefaultValueResolvedToStringChecker
      extends AbstractGenericDefaultValueChecker<String> {