code: def setUp(self):
      super().setUp()
      if combinations.in_main_process():
          num_gpus = combinations.env().total_phsyical_gpus
          if num_gpus != 2 and num_gpus != 4:
              self.skipTest("requires 2 or 4 GPUs")
  
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 1 for calling the ShareGPUTest obj's underlying member method code with example usage: obj.setUp() without return types