code: def make_reward_filtered(env, reward_filter):
      old_step = env.step
  
      def step(action):
          observation, reward, done, info = old_step(action)
          reward = reward_filter(reward)
          return observation, reward, done, info
  
      env.step = step
  
imports: import numpy
label_desc: Use image node_id 4 for calling a global function with example usage: make_reward_filtered(env, reward_filter) and returns: observation,  reward,  done,  info