'Test that a unit kernel with three elements returns the same array
(except when boundary is None).'

@pytest.mark.parametrize(u'boundary', BOUNDARY_OPTIONS)
def test_unity_3(self, boundary):

    x = np.array([1.0, 2.0, 3.0], dtype=u'>f8')
    y = np.array([0.0, 1.0, 0.0], dtype=u'>f8')
    z = convolve(x, y, boundary=boundary)
    if (boundary is None):
        assert np.all((z == np.array([0.0, 2.0, 0.0], dtype=u'>f8')))
    else:
        assert np.all((z == x))
