code: def test_forward_generator(self):
      fwd = np.vstack(
          list(self.hmm.forward_generator(OBS_SEQ, block_size=5))
      )
      self.assertTrue(np.allclose(fwd, CORRECT_FWD))
  
imports: from __future__ import absolute_import, division, print_function
  import sys
  import unittest
  from madmom.ml.hmm import *
label_desc: Use image node_id 4 for calling the TestHiddenMarkovModelClass obj's underlying member method code with example usage: obj.test_forward_generator() without return types