桥接模式

• Bridge
• 分离抽象和具体(两个维度发展)分别继承，抽象聚合(桥接)具体

• public abstract class Gift {
      GiftImpl impl;
  }
  public class Flower extends GiftImpl {}
  public class WarmGift extends Gift {
      public WarmGift(GiftImpl impl) {
          this.impl = impl;
      }
  }