code: def testAppend(self):
      dlm4 = dlm(self.data[0:11])
      dlm4 + self.trend0
      dlm4.evolveMode("dependent")
      dlm4.fitForwardFilter()
      self.assertEqual(dlm4.n, 11)
  
      dlm4.append(self.data[11:20])
      self.assertEqual(dlm4.n, 20)
      dlm4.fitForwardFilter()
  
      self.dlm1.fitForwardFilter()
      self.assertAlmostEqual(
          np.sum(
              np.array(dlm4.result.filteredObs)
              - np.array(self.dlm1.result.filteredObs)
          ),
          0.0,
      )
  
imports: import numpy
  import unittest
  from pydlm.modeler.trends import trend
  from pydlm.modeler.seasonality import seasonality
  from pydlm.modeler.dynamic import dynamic
  from pydlm.modeler.autoReg import autoReg
  from pydlm.dlm import dlm
label_desc: Use image node_id 6 for calling the testDlm obj's underlying member method code with example usage: obj.testAppend() without return types