:lang(az-Arab-IR), lang="az-Arab-IR"
Ignore this test. (:lang with lang is not supported)
You can only get meaningful results for this test if :lang works with lang, since it checks a detail with regard to that support.
Test passes if you see green below.
Assertion: A :lang value with language, script and region subtags will match a lang attribute value with the same language, script and region subtags.