code: def test_log_pdf_asserts_on_invalid_sample(self):
      d = noncentral_chi2.NoncentralChi2(
          df=13.37, noncentrality=42.0, validate_args=True
      )
  
      with self.assertRaisesOpError("Sample must be non-negative."):
          self.evaluate(d.log_prob([14.2, -5.3]))
  
imports: from absl.testing import parameterized
  import numpy
  from scipy import stats
  import tensorflow
  from tensorflow_probability.python.distributions import noncentral_chi2
  from tensorflow_probability.python.distributions.internal import statistical_testing
  from tensorflow_probability.python.internal import test_util
label_desc: Use image node_id 2 for calling the NoncentralChi2Test obj's underlying member method code with example usage: obj.test_log_pdf_asserts_on_invalid_sample() without return types