### Question:
Decorator extends Group { protected void fireHide() { if (null != callback) { callback.onHide(); } } Decorator(final ItemCallback callback); Decorator setPadding(final double padding); Decorator setItemCallback(final ItemCallback callback); IPrimitive<?> build(final IPrimitive<?> item,
                               final double width,
                               final double height); Rectangle createRectangle(final double width,
                                     final double height); Decorator show(final double x,
                          final double y); Decorator hide();  }### Answer:
@Test public void testFireHide() { decorator.fireHide(); verify(callback).onHide(); }