code: def test_missing_data(self):
      e = ParameterEstimator(
          self.m1, self.d2, state_names={"C": [0, 1]}
      )
      self.assertEqual(e.state_counts("A").values.tolist(), [[1], [1]])
      self.assertEqual(
          e.state_counts("C").values.tolist(),
          [[0, 0, 0, 0], [1, 0, 0, 0]],
      )
  
file_path: pgmpy/pgmpy/tests/test_estimators/test_ParameterEstimator.py
imports: import unittest
  from numpy import NaN
  from pandas import DataFrame
  from pgmpy.estimators import ParameterEstimator
  from pgmpy.models import BayesianNetwork
label_desc: Use image node_id 3 for calling the TestParameterEstimator obj's underlying member method code with example usage: obj.test_missing_data() without return types