def METHOD_NAME(trivariate_data, trend, bandwidth):
    y, x = trivariate_data
    y = np.asarray(y)
    x = np.asarray(x)
    z = np.column_stack([y, x])
    ref_z_a, ref_z_t = z_tests(z, bandwidth, trend)
    z_a = phillips_ouliaris(y, x, trend=trend, bandwidth=bandwidth, test_type="Za")
    z_t = phillips_ouliaris(y, x, trend=trend, bandwidth=bandwidth, test_type="Zt")
    assert_allclose(z_a.stat, ref_z_a)
    assert_allclose(z_t.stat, ref_z_t)
    assert isinstance(z_a.summary(), Summary)
    assert isinstance(z_t.summary(), Summary)