code: def test_gym_preprocessors(self):
      p1 = ModelCatalog.get_preprocessor(gym.make("CartPole-v1"))
      self.assertEqual(type(p1), NoPreprocessor)
  
      p2 = ModelCatalog.get_preprocessor(gym.make("FrozenLake-v1"))
      self.assertEqual(type(p2), OneHotPreprocessor)
  
      p3 = ModelCatalog.get_preprocessor(
          gym.make("ALE/MsPacman-ram-v5")
      )
      self.assertEqual(type(p3), AtariRamPreprocessor)
  
      p4 = ModelCatalog.get_preprocessor(
          gym.make(
              "ALE/MsPacman-v5",
              frameskip=1,
          )
      )
      self.assertEqual(type(p4), GenericPixelPreprocessor)
  
imports: import gymnasium
  from gymnasium.spaces import Box, Dict, Discrete, MultiDiscrete, Tuple, MultiBinary
  import numpy
  import unittest
  import ray
  import ray.rllib.algorithms.ppo
  from ray.rllib.models.catalog import ModelCatalog
  from ray.rllib.models.preprocessors import DictFlatteningPreprocessor, get_preprocessor, NoPreprocessor, TupleFlatteningPreprocessor, OneHotPreprocessor, AtariRamPreprocessor, GenericPixelPreprocessor, MultiBinaryPreprocessor
  from ray.rllib.utils.test_utils import check, check_compute_single_action, check_train_results, framework_iterator
  from ray.rllib.utils.framework import try_import_tf
label_desc: Use image node_id 5 for calling the TestPreprocessors obj's underlying member method code with example usage: obj.test_gym_preprocessors() without return types