code: def __init__(self, nr_eval, input_names, output_names, get_player_fn):
      self.eval_episode = nr_eval
      self.input_names = input_names
      self.output_names = output_names
      self.get_player_fn = get_player_fn
  
file_path: tensorpack/examples/DeepQNetwork/common.py
imports: import multiprocessing
  import numpy
  import random
  import time
  from six.moves import queue
  from tensorpack.callbacks import Callback
  from tensorpack.utils import logger, get_tqdm
  from tensorpack.utils.concurrency import ShareSessionThread, StoppableThread
  from tensorpack.utils.stats import StatCounter
label_desc: Use image node_id 1 to create a new Evaluator object from inherited base classes: Callback with example: obj = Evaluator(nr_eval, input_names, output_names, get_player_fn)