code: def testGammaGammaMeanAllDefined(self):
      alpha_v = np.array([2.0, 4.0])
      alpha0_v = np.array([3.0, 6.0])
      beta0_v = np.array([4.0, 8.0])
      expected_mean = alpha_v * beta0_v / (alpha0_v - 1.0)
  
      gg = gamma_gamma.GammaGamma(
          concentration=alpha_v,
          mixing_concentration=alpha0_v,
          mixing_rate=beta0_v,
          validate_args=True,
      )
      self.assertEqual(gg.mean().shape, (2,))
      self.assertAllClose(self.evaluate(gg.mean()), expected_mean)
  
file_path: probability/tensorflow_probability/python/distributions/gamma_gamma_test.py
imports: import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.distributions import gamma_gamma
  from tensorflow_probability.python.internal import test_util
label_desc: Use image node_id 8 for calling the GammaGammaTest obj's underlying member method code with example usage: obj.testGammaGammaMeanAllDefined() without return types