code: def testTemperaturePositive(self):
      temperature = tf.Variable(0.0)
      low = [1.0, 2.0, 3.0]
      peak = [2.0, 3.0, 4.0]
      high = [3.0, 4.0, 5.0]
      self.evaluate(temperature.initializer)
      with self.assertRaisesOpError("`temperature` must be positive."):
          dist = pert.PERT(
              low, peak, high, temperature, validate_args=True
          )
          self.evaluate(dist.sample(1, seed=test_util.test_seed()))
  
imports: import numpy
  from scipy import stats
  import tensorflow.compat.v2
  from tensorflow_probability.python.distributions import pert
  from tensorflow_probability.python.distributions.internal import statistical_testing
  from tensorflow_probability.python.internal import assert_util
  from tensorflow_probability.python.internal import test_util
label_desc: Use image node_id 10 for calling the PERTTest obj's underlying member method code with example usage: obj.testTemperaturePositive() without return types