def METHOD_NAME(self):
    store = self.StoreClass()
    store.setsourcelanguage("nl")
    # Check language auto_detection
    store.filename = "Project/Localizable.stringsdict"
    assert store.gettargetlanguage() == "nl"
    # Clear cache
    store.settargetlanguage(None)
    store.filename = "invalid_filename"
    assert store.gettargetlanguage() == "nl"