code: def testNegativeScaleSkewnessFails(self):
      with self.assertRaisesOpError(
          "Argument `scale` must be positive."
      ):
          dist = two_piece_normal.TwoPieceNormal(
              loc=[0.0],
              scale=[-1.0],
              skewness=[1.0],
              validate_args=True,
          )
          self.evaluate(dist.mean())
  
      with self.assertRaisesOpError(
          "Argument `skewness` must be positive."
      ):
          dist = two_piece_normal.TwoPieceNormal(
              loc=[0.0],
              scale=[1.0],
              skewness=[-1.0],
              validate_args=True,
          )
          self.evaluate(dist.mean())
  
imports: import itertools
  from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.distributions import two_piece_normal
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.math import gradient
label_desc: Use image node_id 22 for calling the _TwoPieceNormalTest obj's underlying member method code with example usage: obj.testNegativeScaleSkewnessFails() without return types