def _sdk_subdir(self):
        """
        Microsoft Windows SDK version subdir.

        Return
        ------
        str
            subdir
        """
        ucrtver = self.si.WindowsSdkLastVersion
        return ('%s\\' % ucrtver) if ucrtver else ''

        Microsoft Windows SDK version subdir.

        Return
        ------
        str
            subdir
        
product/gradle-plugin/src/main/python/setuptools/msvc.py