Convert ListView to ExpandableListView

I've got an Activity with a ListView, filled with the help of an Adapter, that extends a param开发者_JAVA技巧eterized ArrayAdapter<A>. Class A, that parameterizes this Adapter encapsulates a List of objects of class B. I want my ExpandableListView to contain objects of class A as groups and objects of class B to be their children. Is there a simple way to perform this conversion? I was not able to find any classes, implementing ExpandableListAdapter, that can be parameterized.