class_docstr: gym.Env wrapper for resizing frame to (width, height).
  
  Only works with gym.spaces.Box environment with 2D single channel frames.
  
  Example:
      | env = gym.make('Env')
      | # env.observation_space = (100, 100)
      | env_wrapped = Resize(gym.make('Env'), width=64, height=64)
      | # env.observation_space = (64, 64)
  
  Args:
      env: gym.Env to wrap.
      width: resized frame width.
      height: resized frame height.
  
  Raises:
      ValueError: If observation space shape is not 2
          or environment is not gym.spaces.Box.
docstr: gym.Env observation space.
docstr_tok: ["gym.Env","observation","space","."]
code: def observation_space(self):
      """gym.Env observation space."""
      return self._observation_space
  
file_path: garage/src/garage/envs/wrappers/resize.py
imports: import warnings
  import gym
  import gym.spaces
  import numpy
  from skimage import img_as_ubyte
  from skimage.transform import resize
label_desc: Use image node_id 2 for calling the Resize obj's underlying member method code with example usage: obj.observation_space() and returns: self