code: def _init_shape(self, obs_space, options):
      return [1]
  
imports: from functools import partial
  from gymnasium.spaces import Box, Dict, Discrete, Tuple
  import numpy
  import unittest
  import ray
  from ray.rllib.models import ActionDistribution, ModelCatalog, MODEL_DEFAULTS
  from ray.rllib.models.preprocessors import Preprocessor, TupleFlatteningPreprocessor
  from ray.rllib.models.tf.tf_action_dist import MultiActionDistribution, TFActionDistribution
  from ray.rllib.models.tf.tf_modelv2 import TFModelV2
  from ray.rllib.utils.annotations import override
  from ray.rllib.utils.framework import try_import_tf, try_import_torch
  from ray.rllib.utils.spaces.space_utils import get_dummy_batch_for_space
  from ray.rllib.utils.torch_utils import convert_to_torch_tensor
label_desc: Use image node_id 1 for calling the CustomPreprocessor2 obj's underlying member method code with example usage: obj._init_shape(obs_space, options) and returns: list