code: def load_model(model_dir: str) -> Tuple[np.ndarray, np.ndarray]:
      """Load policy parameters from the specified directory.
  
      Args:
          model_dir - Directory to load the model from.
      Returns:
          A pair of parameters, the shapes of which are
          (param_size,) and (1 + 2 * obs_params_size,).
      """
  
      model_file = os.path.join(model_dir, "model.npz")
      if not os.path.exists(model_file):
          raise ValueError("Model file {} does not exist.")
      with np.load(model_file) as data:
          params = data["params"]
          obs_params = data["obs_params"]
      return params, obs_params
  
file_path: evojax/evojax/util.py
imports: import os
  import logging
  import numpy
  from typing import Union
  from typing import Tuple
  from typing import Callable
  import jax.numpy
  from jax import tree_util
  from flax.core import FrozenDict
label_desc: Use image node_id 3 for calling a global function with example usage: load_model(model_dir) and returns: params,  obs_params