@Test public void testEquals() { EqualsTester tester = new EqualsTester(); tester.addEqualityGroup(Letter.A, Letter.valueOf("A"), Letter.valueOfStrict("A")); tester.addEqualityGroup(Letter.B, Letter.valueOf("B"), Letter.valueOfStrict("B")); tester.addEqualityGroup(Letter.C, Letter.valueOf("C"), Letter.valueOfStrict("C")); tester.addEqualityGroup( Letter.valueOf("NonExistentLetter"), Letter.valueOf("NonExistentLetter")); }