code: def test_sample_less_arg(self, random_state):
      model = MC(["a", "b"], [2, 2])
      random_state.return_value = [State("a", 0), State("b", 1)]
      sample = model.sample(size=1)
      random_state.assert_called_once_with(model)
      self.assertEqual(model.state, random_state.return_value)
      self.assertEqual(len(sample), 1)
      self.assertEqual(list(sample.columns), ["a", "b"])
      self.assertEqual(list(sample.loc[0]), [0, 1])
  
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 25 for calling the TestMarkovChain obj's underlying member method code with example usage: obj.test_sample_less_arg(random_state) without return types