[Click] Require a specific element to be included?

[Markku Savela]

For example, my elements would need IP6Address services (element), but
nothing else from ip6 module.

If I put

ELEMENT_REQUIRES(IP6Address)

my element wont get compiled unless I also configure IP6.

It would be nice, if I could just say something like

ELEMENT_INCLUDE(IP6Address)

and it would add this to the compiled and linked elements
(elements.conf?).

Or is there already such mechanism, which I just didn't find
yet?