Validations extends HashSet<Validation> { public static ValidationBuilder single() { return new ValidationBuilder(); } private  Validations(); static ValidationBuilder single(); static ValidationsBuilder builder(); boolean allowsUnrecognizedPaths(); Set<String> getOwnValidatingPaths();  }
@Test public void testValidationBuilder() { Validation v = Validations.single().mandatoryPath("mandatory"); assertEquals(v.getKnownPaths(), Sets.newHashSet("mandatory")); }