HierarchicalContainer.getProperty Type Conversion

Hey Short and simple quesiton

I'm putting an id of type Long into an Item(com.vaadin.data.Item) in a HierachicalContainer that is used in a tree.

item.getItemProperty(IVRContainer.ID).setValue(ivr.getId());

where ivr.getId() is a Long

When the node in the tree is clicked I fetch the property from the Item and the return type is String and not Long.

public void itemClick(ItemClickEvent event) {
	Item item = event.getItem();
	Object itemId = item.getItemProperty(IVRContainer.ID).getValue();
	if(event.isDoubleClick()){
		if (itemId instanceof Long){
			...this block never excutes due to itemId being a String now
			.....

This is annoying, is this a bug?

Cheers,
Matt