code: def testNegativetailweightFails(self):
      with self.assertRaisesOpError(
          "Argument `tailweight` must be positive."
      ):
          dist = johnson_su.JohnsonSU(
              skewness=[1.0],
              tailweight=[-1.0],
              loc=[1.0],
              scale=[5.0],
              validate_args=True,
              name="D",
          )
          self.evaluate(dist.mean())
  
imports: import math
  import numpy
  from scipy import stats
  import tensorflow.compat.v1
  import tensorflow.compat.v2
  from tensorflow_probability.python.distributions import johnson_su
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.math import gradient
label_desc: Use image node_id 24 for calling the JohnsonSUTest obj's underlying member method code with example usage: obj.testNegativetailweightFails() without return types