def test_moveToExistsCache(self):
        """
        A L{FilePath} that has been moved aside with L{FilePath.moveTo} no
        longer registers as existing.  Its previously non-existent target
        exists, though, as it was created by the call to C{moveTo}.
        """
        fp = filepath.FilePath(self.mktemp())
        fp2 = filepath.FilePath(self.mktemp())
        fp.touch()

        # Both a sanity check (make sure the file status looks right) and an
        # enticement for stat-caching logic to kick in and remember that these
        # exist / don't exist.
        self.assertTrue(fp.exists())
        self.assertFalse(fp2.exists())

        fp.moveTo(fp2)
        self.assertFalse(fp.exists())
        self.assertTrue(fp2.exists())

        A L{FilePath} that has been moved aside with L{FilePath.moveTo} no
        longer registers as existing.  Its previously non-existent target
        exists, though, as it was created by the call to C{moveTo}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_paths.py