public void test_negate() { ObjIntPredicate<String> fn1 = (a, b) -> b > 3; ObjIntPredicate<String> negate = fn1.negate(); assertEquals(fn1.test("a", 2), false); assertEquals(fn1.test("a", 4), true); assertEquals(negate.test("a", 2), true); assertEquals(negate.test("a", 4), false); }