class_docstr: Common tests for noisy mixture distributions.
code: def test_sampling_works(self):
      dist = self.dist_cls(loc=[[0]], scale=[3, 5], weight=[0.2, 0.8])
      sample = dist.sample((5, 4))
      self.assertEqual(sample.shape, (5, 4, 1))
  
imports: import tensorflow
  from tensorflow_compression.python.distributions import helpers
  from tensorflow_compression.python.distributions import uniform_noise
label_desc: Use image node_id 5 for calling the MixtureTest obj's underlying member method code with example usage: obj.test_sampling_works() without return types