What's the purpose the hook method showing in a class definition?

[jfong at ms4.hinet.net]

For the two examples below:
(1)
>>> class A:
...     def foo(self):
...         self.goo()
...
>>> class B(A):
...     def goo(self):
...         print(1)
...

(2)
>>> class A:
...     def foo(self):
...         self.goo()
...     def goo(self): pass
...
>>> class B(A):
...     def goo(self):
...         print(1)
...

Both can get the same result:
>>> b = B()
>>> b.foo()
1
>>>

What's the benefit of having the hook method goo() in class A in example 2?

--Jach