def METHOD_NAME(self):
    m = anisotropy.TetragonalMaterial(3000.0, [1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0])
    self.assertFloatEqual(
        m.isentropic_stiffness_tensor[0][5], -m.isentropic_stiffness_tensor[1][5]
    )