FunctionalUtils { public static <T> Predicate<T> not(Predicate<T> predicate) { return predicate.negate(); } private  FunctionalUtils(); static Predicate<T> not(Predicate<T> predicate); @SuppressWarnings("unchecked") static Predicate<T> alwaysTrue();  }
@Test public void negatesPredicate() { assertTrue(FunctionalUtils.not(test -> false).test("")); }