code: def testMean(self):
      dist = self.make_two_piece_normals()
  
      mean = self.evaluate(dist.mean())
      expected_mean = np.array(
          [-1.6543264, 3.0, 7.612733], dtype=self.dtype
      )
  
      self.assertAllEqual(mean.shape, expected_mean.shape)
      self.assertAllClose(mean, expected_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 14 for calling the _TwoPieceNormalTest obj's underlying member method code with example usage: obj.testMean() without return types