code: def parse_agent(agent):
      return {
          "IQN": chainerrl.agents.IQN,
          "DoubleIQN": chainerrl.agents.DoubleIQN,
      }[agent]
  
file_path: chainerrl/examples/atari/train_double_iqn.py
imports: import argparse
  import functools
  import json
  import os
  import chainer
  import chainer.functions
  import chainer.links
  import gym
  import numpy
  import chainerrl
  from chainerrl import experiments
  from chainerrl import explorers
  from chainerrl import misc
  from chainerrl import replay_buffer
  from chainerrl.wrappers import atari_wrappers
label_desc: Use image node_id 1 for calling a global function with example usage: parse_agent(agent) and returns: dict