code: def phi(x):
      # Feature extractor
      return np.asarray(x, dtype=np.float32) / 255
  
imports: import argparse
  import functools
  import logging
  import chainer
  import numpy
  import chainerrl
  from chainerrl.agents import a2c
  from chainerrl import experiments
  from chainerrl import links
  from chainerrl import misc
  from chainerrl.optimizers.nonbias_weight_decay import NonbiasWeightDecay
  from chainerrl.optimizers import rmsprop_async
  from chainerrl import policy
  from chainerrl import v_function
  from chainerrl.wrappers import atari_wrappers
label_desc: Use image node_id 1 for calling a global function with example usage: phi(x) and returns: unknown