code: def testClusterParamsAreOptional(self, distribution):
      # If combinations library doesn't raise an exception, the test is passed.
      pass
  
imports: import importlib
  import os
  import sys
  import unittest
  from absl.testing import parameterized
  from tensorflow.python.distribute import combinations
  from tensorflow.python.distribute import test_util
  from tensorflow.python.distribute.cluster_resolver import tfconfig_cluster_resolver
  from tensorflow.python.eager import context
  from tensorflow.python.framework import combinations
  from tensorflow.python.platform import test
label_desc: Use image node_id 4 for calling the ClusterCombinationTest obj's underlying member method code with example usage: obj.testClusterParamsAreOptional(distribution) without return types