return OptionalInt.of(generateInt());
  }

  @Generates
  OptionalLong generateOptionalLong() {
    return OptionalLong.of(generateLong());
  }

  @Generates
  OptionalDouble generateOptionalDouble() {
    return OptionalDouble.of(generateDouble());
  }

  // common.base
  @Empty
  <T> com.google.common.base.Optional<T> generateGoogleOptional() {