def test_stencil3(self):
        """Tests whether a non-zero optional cval argument to the stencil
        decorator works.  Also tests integer result type.
        """
        def test_seq(n):
            A = np.arange(n**2).reshape((n, n))
            B = stencil3_kernel(A)
            return B

        test_njit = njit(test_seq)
        test_par = njit(test_seq, parallel=True)

        n = 5
        seq_res = test_seq(n)
        njit_res = test_njit(n)
        par_res = test_par(n)

        self.assertTrue(seq_res[0, 0] == 1.0 and seq_res[4, 4] == 1.0)
        self.assertTrue(njit_res[0, 0] == 1.0 and njit_res[4, 4] == 1.0)
        self.assertTrue(par_res[0, 0] == 1.0 and par_res[4, 4] == 1.0)
Tests whether a non-zero optional cval argument to the stencil
        decorator works.  Also tests integer result type.
        
numba/tests/test_stencils.py