code: def testRaisesIfCovarianceOperatorNotProvided(self):
      with self.assertRaisesRegex(ValueError, "Missing.*cov_operator"):
          MultivariateNormalLowRankUpdateLinearOperatorCovariance(
              loc=[1.0, 1.0], cov_operator=None, validate_args=True
          )
  
imports: import collections
  from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v1
  import tensorflow.compat.v2
  from tensorflow_probability.python.distributions import mvn_low_rank_update_linear_operator_covariance
  from tensorflow_probability.python.distributions import mvn_tril
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.stats import sample_stats
label_desc: Use image node_id 5 for calling the MultivariateNormalLowRankUpdateLinearOperatorCovarianceTest obj's underlying member method code with example usage: obj.testRaisesIfCovarianceOperatorNotProvided() without return types