def test_readlinkENOENT(self):
        """
        L{lockfile.readlink} raises L{OSError} with C{errno} set to L{ENOENT}
        when an attempt is made to read a symlink which does not exist.
        """
        name = self.mktemp()
        exc = self.assertRaises(OSError, lockfile.readlink, name)
        self.assertEqual(exc.errno, errno.ENOENT)

        L{lockfile.readlink} raises L{OSError} with C{errno} set to L{ENOENT}
        when an attempt is made to read a symlink which does not exist.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_lockfile.py