code: def _encode_obs(self, obs):
      new_obs = np.ones(self.env.observation_space.n)
      new_obs[obs] = 1.0
      return new_obs
  
file_path: ray/python/ray/rllib/examples/env/look_and_push.py
imports: import gymnasium
  import numpy
label_desc: Use image node_id 4 for calling the OneHot obj's underlying member method code with example usage: obj._encode_obs(obs) and returns: new_obs