code: def test_simple_scenario(self):
      from packaging import version
  
      n_envs = 3
      envs = [gym.make("CartPole-v1")] * n_envs
      rl_scenario = RLScenario(
          envs, n_parallel_envs=1, task_labels=True, eval_envs=[]
      )
      tr_stream = rl_scenario.train_stream
      assert len(tr_stream) == n_envs
      assert not len(rl_scenario.eval_stream)
  
      for i, exp in enumerate(tr_stream):
          assert exp.current_experience == i
          env = exp.environment
          # same envs
          assert exp.task_label == 0
          assert isinstance(env, gym.Env)
          obs = env.reset()
          if version.parse(gym.__version__) >= version.parse("0.26.0"):
              self.assertIsInstance(obs[0], np.ndarray)
              self.assertIsInstance(obs[1], dict)
          else:
              self.assertIsInstance(obs, np.ndarray)
  
imports: import unittest
  import numpy
label_desc: Use image node_id 1 for calling the RLScenarioTests obj's underlying member method code with example usage: obj.test_simple_scenario() without return types