code: def testMissingData(self):
      dlm = builder()
      dlm.add(self.trend0)
      dlm.initialize()
  
      self.kf0.forwardFilter(dlm.model, 1)
      self.assertAlmostEqual(dlm.model.obs[0, 0], 1.0)
      self.assertAlmostEqual(dlm.model.obsVar[0, 0], 1.0)
  
      self.kf0.forwardFilter(dlm.model, None)
      self.assertAlmostEqual(dlm.model.obs[0, 0], 1.0)
      self.assertAlmostEqual(dlm.model.obsVar[0, 0] / 1e10, 0.5)
  
      self.kf0.forwardFilter(dlm.model, None)
      self.assertAlmostEqual(dlm.model.obs[0, 0], 1.0)
      self.assertAlmostEqual(dlm.model.obsVar[0, 0] / 1e10, 0.5)
  
      self.kf0.forwardFilter(dlm.model, 0)
      self.assertAlmostEqual(dlm.model.obs[0, 0], 0.0)
  
file_path: pydlm/tests/base/testKalmanFilter.py
imports: import numpy
  import unittest
  from pydlm.modeler.trends import trend
  from pydlm.modeler.seasonality import seasonality
  from pydlm.modeler.builder import builder
  from pydlm.base.kalmanFilter import kalmanFilter
label_desc: Use image node_id 6 for calling the testKalmanFilter obj's underlying member method code with example usage: obj.testMissingData() without return types