Another the to explain:
member variales are static-linked as well as the private methods,it is said that when using "new" to construct an instance,the member variables and preivate methods are definite.but other methods not,it is linked at runtime
in this case,method g() in Super already knows where to invoke the f(),because f() is private.it is already linked to the g() method as well as the instance.
so is clear
