Closure ： You can use another function in one function as the return value of this function .
Closure ：
Not closure ：
There is no environment variable carried by the function n return 
Decorator ： Write the functions you want to add in it
Add a before the function to be modified @ Add the name of the decorator
Realize to my_fun The decoration of 、 enhance
benefits ： Using decorator can not change some of the original calls 
Print out the time it takes after hibernation 
