[Zope] How to Add an object at the root of a zope tree

How to add an object at the root of a Zope tree even if the method has been called inside a subfolder ? I tried location=aq_parent(getattr(self, 'Control_Panel')) it returns the folder where is located the method. (I suppose that 'Control_Panel' is acquired) I tried : location=aq_parent(aq_inner(getattr(self, 'Control_Panel'))) It raises an error : 'aq_parent is not defined'. It's the same with aq_base. Is there a function returning the absolute root ? TIA Andre