code: def test_cases(self):
      for constrained in self.constrained_cases:
          unconstrained = tools.unconstrain_stationary_univariate(
              constrained
          )  # noqa:E501
          reconstrained = tools.constrain_stationary_univariate(
              unconstrained
          )  # noqa:E501
          assert_allclose(reconstrained, constrained)
  
      for unconstrained in self.unconstrained_cases:
          constrained = tools.constrain_stationary_univariate(
              unconstrained
          )
          reunconstrained = tools.unconstrain_stationary_univariate(
              constrained
          )  # noqa:E501
          assert_allclose(reunconstrained, unconstrained)
  
imports: import pytest
  import numpy
  from numpy.testing import assert_allclose, assert_equal, assert_array_less, assert_array_equal, assert_almost_equal
  import pandas
  from scipy.linalg import solve_discrete_lyapunov
  from statsmodels.tsa.statespace import tools
  from statsmodels.tsa.stattools import acovf
label_desc: Use image node_id 1 for calling the TestStationaryUnivariate obj's underlying member method code with example usage: obj.test_cases() without return types