code: def testAssertValidSample(self):
      dist = lognormal.LogNormal(
          loc=[-3.0, 1.0, 4.0], scale=2.0, validate_args=True
      )
      with self.assertRaisesOpError("Sample must be non-negative."):
          self.evaluate(dist.cdf([3.0, -0.2, 1.0]))
  
file_path: probability/tensorflow_probability/python/distributions/lognormal_test.py
imports: import numpy
  from scipy import stats
  import tensorflow.compat.v2
  from tensorflow_probability.python.distributions import kullback_leibler
  from tensorflow_probability.python.distributions import lognormal
  from tensorflow_probability.python.distributions import normal
  from tensorflow_probability.python.internal import test_util
label_desc: Use image node_id 7 for calling the LogNormalTest obj's underlying member method code with example usage: obj.testAssertValidSample() without return types