code: def testNotPositiveDefinite(self):
      with self.assertRaisesRegexp(
          ValueError, "`scale` must be non-singular."
      ):
          mvst.MultivariateStudentTLinearOperator(
              loc=self._input([0.0]),
              df=self._input(1.0),
              scale=tf.linalg.LinearOperatorDiag(self._input([1.0])),
              validate_args=True,
          )
  
imports: from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v1
  import tensorflow.compat.v2
  from tensorflow_probability.python.bijectors import exp
  from tensorflow_probability.python.distributions import multivariate_student_t
  from tensorflow_probability.python.distributions import student_t
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.math import gradient
  from tensorflow_probability.python.util import deferred_tensor
label_desc: Use image node_id 5 for calling the MultivariateStudentTTestFloat32StaticShape obj's underlying member method code with example usage: obj.testNotPositiveDefinite() without return types