The Decorator pattern
It was a hectic Monday morning for Kitty and Phoebe. Over the weekend, Kitty had ridden a prototype mountain bike around some of the trails near her home in the rocky desert of West Texas. She wanted a challenging test, so she chose Black Gap Road in Big Bend, a US national park. Big Bend derives its name from a large bend in the Rio Grande river, which forms the park’s border, as well as the United States’ southern border with Mexico. Black Gap Road is well known as a challenging trail. It has washouts, shallow creek crossings, and an actual gap (after which the road is named). The gap consists of a narrow passage between two large hills formed from volcanic rock. In the middle of the gap is a ledge that drops about 3 feet (about 1 meter) into the next section. Kitty had driven over the ledge in her Jeep many times, but never on a bike. She misjudged the drop and wound up flat on her back. After catching her breath, she got back on her bicycle and...