版权声明:不自见故明;不自是故彰;不自伐故有功;不自矜故长; https://blog.csdn.net/LightUpHeaven/article/details/84778624
11.1.字段上移(Pull Up Field)
11.2.函数上移(Pull Up Method)
11.3.构造函数本体上移(Pull Up Constructor Body)
11.4.函数下降(Push Down Method)
11.5.字段下移(Push Down Field)
11.6.提炼子类(Extract Subclass)