def test_isVistaConsistency(self):
        """
        Verify consistency of L{Platform.isVista}: it can only be C{True} if
        L{Platform.isWinNT} and L{Platform.isWindows} are C{True}.
        """
        platform = Platform()
        if platform.isVista():
            self.assertTrue(platform.isWinNT())
            self.assertTrue(platform.isWindows())
            self.assertFalse(platform.isMacOSX())

        Verify consistency of L{Platform.isVista}: it can only be C{True} if
        L{Platform.isWinNT} and L{Platform.isWindows} are C{True}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_runtime.py