def test_shift1(self):
        def test_impl(n):
            df = pd.DataFrame({'A': np.arange(n) + 1.0, 'B': np.random.ranf(n)})
            Ac = df.A.shift(1)
            return Ac.sum()

        hpat_func = self.jit(test_impl)
        n = 11
        self.assertEqual(hpat_func(n), test_impl(n))
        self.assertEqual(count_array_REPs(), 0)
        self.assertEqual(count_parfor_REPs(), 0)