### Question:
ShortWrapper extends AbstractWrapper<Short> implements NumberWrapper<Short> { @Override public void decrement() { Short value = doGet(); if (value != null) { doSet((short) (value - 1)); } } ShortWrapper();  ShortWrapper(Short value); @Override void set(Number v); @Override void increment(); @Override void decrement(); @Override R accept(WrapperVisitor<R, P, Q, TH> visitor, P p, Q q);  }### Answer:
@Test public void testDecrement() { ShortWrapper wrapper = new ShortWrapper((short) 10); wrapper.decrement(); assertEquals(new Short((short) 9), wrapper.get()); }