for test in testcases:
        if hasattr(test, 'groups'):
            if any(group in test.groups for group in mandatory_classes):
                continue
            if all(group in test.groups for group in ['event', 'validation'] and group not in ['remain']) or all(
                    group in test.groups for group in ['event', 'clean']) or all(
                group in test.groups for group in ['backend', 'validation']) :
                excluded_classes.append(test)
            continue