def isnosetest(self, obj: object) -> bool:
        """Look for the __test__ attribute, which is applied by the
        @nose.tools.istest decorator.
        """
        # We explicitly check for "is True" here to not mistakenly treat
        # classes with a custom __getattr__ returning something truthy (like a
        # function) as test classes.
        return safe_getattr(obj, "__test__", False) is True
Look for the __test__ attribute, which is applied by the
        @nose.tools.istest decorator.
        
src/_pytest/python.py