### Question:
MoneyBag implements IMoney { public IMoney subtract(IMoney m) { return add(m.negate()); }  IMoney add(IMoney m); IMoney addMoney(Money m); IMoney addMoneyBag(MoneyBag s); boolean equals(Object anObject); int hashCode(); boolean isZero(); IMoney multiply(int factor); IMoney negate(); IMoney subtract(IMoney m); String toString(); void appendTo(MoneyBag m);  }### Answer:
@Test public void testNormalize2() { Money expected = new Money(7, "USD"); assertEquals(expected, fMB1.subtract(f12CHF)); }
@Test public void testSimpleSubtract() { Money expected = new Money(2, "CHF"); assertEquals(expected, f14CHF.subtract(f12CHF)); }