class_docstr: Environment wrapper for Multigrid environments.
  
  Note: the main difference with vanilla GymWrapper is that reward_spec() is
  overridden and rewards are cast to np.arrays in step()
code: def close(self):
      self._environment.close()
  
imports: from typing import Any, Dict, List, Optional
  import warnings
  from acme import specs
  from acme import types
  from acme import wrappers
  from acme.multiagent import types
  from acme.wrappers import multiagent_dict_key_wrapper
  import dm_env
  import gym
  from gym import spaces
  import jax
  import numpy
  import tree
label_desc: Use image node_id 11 for calling the MultigridWrapper obj's underlying member method code with example usage: obj.close() without return types