code: def test_do_backward_scaling_pass(self):
      log_prob, fwdlattice, scaling_factors = _hmmc.forward_scaling(
          self.hmm.startprob_, self.hmm.transmat_, self.frameprob
      )
      bwdlattice = _hmmc.backward_scaling(
          self.hmm.startprob_,
          self.hmm.transmat_,
          self.frameprob,
          scaling_factors,
      )
      refbwdlattice = np.array(
          [
              [0.0661, 0.0455],
              [0.0906, 0.1503],
              [0.4593, 0.2437],
              [0.6900, 0.4100],
              [1.0000, 1.0000],
          ]
      )
      scaling_factors = np.cumprod(scaling_factors[::-1])[::-1]
      bwdlattice_scaled = bwdlattice / scaling_factors[:, None]
      # Answer will be equivalent when the scaling factor is accounted for
      assert_allclose(bwdlattice_scaled, refbwdlattice, 4)
  
imports: import numpy
  from numpy.testing import assert_allclose
  import pytest
  from scipy import special
  from hmmlearn.base import BaseHMM, ConvergenceMonitor
  from hmmlearn import _hmmc
label_desc: Use image node_id 4 for calling the TestBaseAgainstWikipedia obj's underlying member method code with example usage: obj.test_do_backward_scaling_pass() without return types