@Test
public void testConvertToKnownLocale() throws Exception {
assertEquals(Optional.of("en"), Languages.convertToKnownLocale("en"));
assertEquals(Optional.of("en"), Languages.convertToKnownLocale("en_US"));
assertEquals(Optional.of("de"), Languages.convertToKnownLocale("de_DE"));
assertEquals(Optional.empty(), Languages.convertToKnownLocale("WHATEVER"));
}
@Test(expected = NullPointerException.class)
public void testConvertToKnownLocaleNull() {
Languages.convertToKnownLocale(null);
}