@Test
public void testMultiply() throws Exception {
MutableMoney m1 = MutableMoney.of(1, 20);
assertEquals(MutableMoney.of(2, 40), m1.multiply(2));
m1 = MutableMoney.of(-1, 20);
assertEquals(MutableMoney.of(2, 40).negate(), m1.multiply(2));
}
