any SOURCE * query example/test-case?

Can anybody provide (or think of) an example query/test-case using 
SOURCE * (first part of production 6 - special case where ?src matched 
any source I guess) which fits the current design document?

	http://www.w3.org/2001/sw/DataAccess/rq23/

I could not find any in the current doc and/or in the test-repository...

thanks

Alberto