The description of the mentioned test-case is:
"Test that counts feature dependencies associated with testcases"

Still, the test-case is:

declare namespace fots = "http://www.w3.org/2010/09/qt-fots-catalog";
let $testfiles := //fots:test-set/@file/doc(resolve-uri(., base-uri(..)))
let $testsets := $testfiles/fots:test-set
for $testset in $testsets
return $testsets/@name

It could be that the test-case is wrong because of a TYPO:
because
return $testsets/@name

should have been
return $testset/@name

Also the test-case seems wrong because it does not do what the description suggests.