### Question:
MoneyBag implements IMoney { private IMoney simplify() { if (fMonies.size() == 1) { return fMonies.elements().nextElement(); } return this; }  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 testSimplify() { IMoney money = MoneyBag.create(new Money(26, "CHF"), new Money(28, "CHF")); assertEquals(new Money(54, "CHF"), money); }