Optional<Integer> optionalInt = getSomeOptionalInt();
    // Number value = optionalInt.or(0.5); // error
  }

  @SuppressWarnings("unused") // compilation test
  public void testSampleCodeError2() {
    FluentIterable<? extends Number> numbers = getSomeNumbers();
    Optional<? extends Number> first = numbers.first();
    // Number value = first.or(0.5); // error
  }