code: def testMoyalMean(self):
      batch_size = 6
      loc = np.array([[2.0, 4.0, 5.0]] * batch_size, dtype=self.dtype)
      scale = np.array([1.0], dtype=self.dtype)
  
      dist = moyal.Moyal(
          loc=self.make_tensor(loc),
          scale=self.make_tensor(scale),
          validate_args=True,
      )
      self.assertAllClose(
          self.evaluate(dist.mean()),
          stats.moyal.mean(loc=loc, scale=scale),
      )
  
imports: import numpy
  from scipy import stats
  import tensorflow.compat.v1
  import tensorflow.compat.v2
  from tensorflow_probability.python.distributions import kullback_leibler
  from tensorflow_probability.python.distributions import moyal
  from tensorflow_probability.python.internal import test_util
label_desc: Use image node_id 8 for calling the _MoyalTest obj's underlying member method code with example usage: obj.testMoyalMean() without return types