assert_equal "fr", Locale.available.preferred(Locale.list("fr", "en")).to_s
assert_equal "de", Locale.available.preferred(Locale.list("zh-Hant", "de")).to_s
assert_equal "zh-TW", Locale.available.preferred(Locale.list("zh-Hant-TW", "de")).to_s
assert_equal "fr", Locale.available.preferred(Locale.list("fr", "en")).to_s
assert_equal "de", Locale.available.preferred(Locale.list("zh-Hant", "de")).to_s
assert_equal "zh-TW", Locale.available.preferred(Locale.list("zh-Hant-TW", "de")).to_s