question: private HashMap < Integer , Boolean > generateExpandedStateMap ( ) { HashMap < Integer , Boolean > parentListItemHashMap = new HashMap < > ( ) ; int childCount = 0 ; Object listItem ; ParentWrapper parentWrapper ; int listItemCount = mItemList . size ( ) ; for ( int i = 0 ; i < listItemCount ; i ++ ) { if ( mItemList . get ( i ) != null ) { listItem = getListItem ( i ) ; if ( listItem instanceof ParentWrapper ) { parentWrapper = ( ParentWrapper ) listItem ; parentListItemHashMap . put ( i - childCount , parentWrapper . isExpanded ( ) ) ; } else { childCount ++ ; } } } return parentListItemHashMap ; }
target:  Generates a HashMap used to store expanded state for items in the list on configuration change or whenever onResume is called.