code: def test_check_bad_covariance_type(self, implementation):
      h = self.new_hmm(implementation)
      with pytest.raises(ValueError):
          h.covariance_type = "bad_covariance_type"
          h._check()
  
imports: import numpy
  from numpy.testing import assert_allclose, assert_array_less
  import pytest
  from sklearn.utils import check_random_state
  from ..hmm import GMMHMM
  from .test_gmm_hmm import create_random_gmm
  from .None import assert_log_likelihood_increasing, normalized
label_desc: Use image node_id 2 for calling the GMMHMMTestMixin obj's underlying member method code with example usage: obj.test_check_bad_covariance_type(implementation) without return types