Android: Reason For Calling Superclass?

I'm looking at the Notepad tutorial from the Android developer's site. I have a question about overridden functions calling the super-class of activities. For example, public clas

Solution 1:

Activities have a number of operations they perform throughout their life cycle - some of these are house cleaning (garbage collection), UI stuff, etc.

As far as I know, super.onCreateContextMenu() doesn't have to be called, unlike methods like onCreate, onResume, etc.