code: def test_is_stationarity_success(self):
      model = MC(["intel", "diff"], [2, 3])
      model.set_start_state([State("intel", 0), State("diff", 2)])
      intel_tm = {0: {0: 0.25, 1: 0.75}, 1: {0: 0.5, 1: 0.5}}
      model.add_transition_model("intel", intel_tm)
      diff_tm = {
          0: {0: 0.1, 1: 0.5, 2: 0.4},
          1: {0: 0.2, 1: 0.2, 2: 0.6},
          2: {0: 0.7, 1: 0.15, 2: 0.15},
      }
      model.add_transition_model("diff", diff_tm)
      self.assertTrue(model.is_stationarity)
  
imports: import sys
  import unittest
  import numpy
  from mock import call, patch
  from pandas import DataFrame
  from pgmpy.factors.discrete import State
  from pgmpy.models import MarkovChain
label_desc: Use image node_id 27 for calling the TestMarkovChain obj's underlying member method code with example usage: obj.test_is_stationarity_success() without return types