### Question:
Ack { public static Ack one(int count) { return validate(count == 1); }  static Ack validate(boolean test); static Ack validate(Optional<?> optional); static Ack one(int count); Ack and(Ack ack); Ack or(Ack ack); static final Ack OK; static final Ack NOK; }### Answer:
@Test public void one_0() { assertFalse(Ack.one(0).isSuccess()); }
@Test public void one_1() { assertTrue(Ack.one(1).isSuccess()); }
@Test public void one_more() { assertFalse(Ack.one(2).isSuccess()); }