code: def setUpClass(cls):
      ray.init()
  
file_path: ray/rllib/algorithms/appo/tests/test_appo_learner.py
imports: import unittest
  import numpy
  import tree
  import ray
  import ray.rllib.algorithms.appo
  from ray.rllib.algorithms.appo.tf.appo_tf_learner import LEARNER_RESULTS_CURR_KL_COEFF_KEY
  from ray.rllib.policy.sample_batch import SampleBatch, DEFAULT_POLICY_ID
  from ray.rllib.utils.metrics.learner_info import LEARNER_INFO
  from ray.rllib.utils.framework import try_import_tf
  from ray.rllib.utils.test_utils import framework_iterator
  from ray.rllib.utils.torch_utils import convert_to_torch_tensor
label_desc: Use image node_id 1 for calling the TestAPPOTfLearner obj's underlying member method code with example usage: obj.setUpClass(cls) without return types