getListModel
public HierarchyListItem getListModel(android.widget.BaseAdapter callback,
                                      long actions,
                                      HierarchyListItem.Sort sort)
Returns the model that may be used to build a UI to interact with the overlay. The returned
 item represents the root node to be displayed in the list. If null, the overlay
 will not appear in the list.
- Specified by:
 
getListModel in interface MapOverlay 
- Parameters:
 
callback - A reference to the adapter that will be responsible for displaying the list.
            The overlay may invoke BaseAdapter.notifyDataSetChanged()
            if the list content is externally modified and the adapter should update. 
sort - The preferred sorting order to be used when constructing the list view.
            This argument is a hint and may be ignored in the event that executing the
            specified sort will compromise performance. An ascending alphabetic sort is
            recommended as the default. 
- Returns:
 
- The list model used to build the UI for the overlay or 
null if the
         overlay should not be included in the list.