code: def testExponentialMean(self):
      lam_v = np.array([1.0, 4.0, 2.5])
      exponential = exponential_lib.Exponential(rate=lam_v)
      self.assertEqual(exponential.mean().get_shape(), (3,))
      if not stats:
          return
      expected_mean = stats.expon.mean(scale=1 / lam_v)
      self.assertAllClose(
          self.evaluate(exponential.mean()), expected_mean
      )
  
imports: import importlib
  import numpy
  from tensorflow.python.eager import backprop
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import nn_ops
  from tensorflow.python.ops.distributions import exponential
  from tensorflow.python.platform import test
  from tensorflow.python.platform import tf_logging
label_desc: Use image node_id 5 for calling the ExponentialTest obj's underlying member method code with example usage: obj.testExponentialMean() without return types