title: onAttach(Activity activity) what is this activity in a fragment inside another fragment
body: <p>It sounds me a confusing Question. What is the Activity Object in onAttach method of a fragment which is nested inside a parent Fragment?</p>
  
  <p>I know I can communicate to the parent fragment by using getParentFragment() method.But I  want to know if this activity object in the onAttach returns the FragmentActivity instance or not, so as to have a direct communication (by using interface callback) from a nested fragment to the FragmentActivity.</p>
  
  <p>Sorry for my bad English. I tried my best to convey my thoughts.</p>