说明：  本书是为程序员量身打造的工作利器。有了它你可以安全地改善既有代码的设计，由此可以提供高效而可靠的系统，使纷杂凌乱归于平衡有序，并能最大限度地抑制导常的出现。
(This book is tailored for programmers working weapon. With it you can safely improve the design of existing code, which can provide efficient and reliable system attributed to the confused mess Ping Heng and orderly, and to maximize the suppression guide appears normal.)