def test_sim_updates(self, disc_lr, gen_lr):
    # player order does not matter.
    # the number of updates does not matter for simultaneous updates.
    learning_rates = gan.GANTuple(disc=disc_lr, gen=gen_lr)
    drift_coeffs = drift_utils.get_dd_coeffs(
        None, True, learning_rates, num_updates=None)

    self.assertEqual(drift_coeffs.disc.self_norm, 0.5 * disc_lr)
    self.assertEqual(drift_coeffs.disc.other_norm, 0.0)
    self.assertEqual(drift_coeffs.disc.other_dot_prod, 0.5 * disc_lr)

    self.assertEqual(drift_coeffs.gen.self_norm, 0.5 * gen_lr)
    self.assertEqual(drift_coeffs.gen.other_norm, 0.0)
    self.assertEqual(drift_coeffs.gen.other_dot_prod, 0.5 * gen_lr)