How to use the 'focusedElement(using:)' type method?

Hi everyone,

I found the accessibility focusedElement(using:) type method but cannot find the type element it refers to.
The Apple reference html page isn’t really helpful about it.

Does anyone know how to find this type and what it is exactly, please ?

PS : a workaround is to use directly the objective-C syntax UIAccessibilityFocusedElement(UIAccessibilityNotificationVoiceOverIdentifier) to get the desired result but I’d like to understand the swift syntax.