引用自 Refactoring Improving the Design of Existing Code ---Martin Fowler
1.Extract Method(提炼函数)
2.Inline Method(内联函数)
3.Inline Temp(内联临时变量)
4.Replace Temp with Query(以查询取代临时变量)
5.Introduce Explaining Variable(引入解释性变量)
6.Split Temporary Variable(分解临时变量)
7.Remove Assignments to Parameters(移除对参数的赋值)
8.Replace Method with Method Object(以函数对象取代函数)
9.Substitute Algorithrm(替换算法)