code: def _concat_obs(base_obs, extra_obs):
      return np.append(base_obs, np.expand_dims(extra_obs, 0), axis=0)
  
imports: import dataclasses
  import enum
  from typing import Any, Dict, List, Mapping
  from etils import epath
  import h5py
  import numpy
  import tensorflow_datasets.public_api
  import tree
label_desc: Use image node_id 2 for calling a global function with example usage: _concat_obs(base_obs, extra_obs) and returns: np