@Test
public void testDoesNotAcceptPDFs() {

	ReadingTimeCalculator readingTimeCalculator =
		new ReadingTimeCalculatorImpl();
	Optional<Duration> readingTimeOptional =
		readingTimeCalculator.calculate(
			StringUtil.randomString(), ContentTypes.APPLICATION_PDF,
			LocaleUtil.getDefault());
	Assert.assertFalse(readingTimeOptional.isPresent());
}