
allowDeselect
If this property is activated, the user can deselect all AccordionItems at the same time. Otherwise, only one AccordionItem is selected at a time.
selectedItem
ID of the selected AccordionItem or MultipleAccordionItem. If you are dealing with a MultipleAccordionItem, you also need the lead selection that you get from the node specified in MultipleAccordionItem.dataSource, in order to find out which instance was selected.