def test_symbolicLink(self):
        """
        Verify the behavior of the C{isLink} method against links and
        non-links. Also check that the symbolic link shares the directory
        property with its target.
        """
        s4 = self.path.child(b"sub4")
        s3 = self.path.child(b"sub3")
        self.symlink(s3.path, s4.path)
        self.assertTrue(s4.islink())
        self.assertFalse(s3.islink())
        self.assertTrue(s4.isdir())
        self.assertTrue(s3.isdir())

        Verify the behavior of the C{isLink} method against links and
        non-links. Also check that the symbolic link shares the directory
        property with its target.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_paths.py