code: def __init__(self, ds):
      ProxyDataFlow.__init__(self, ds)
  
imports: import argparse
  import multiprocessing
  import numpy
  import cv2
  import tensorflow
  from scipy.signal import convolve2d
  from tensorpack import *
  from tensorpack.dataflow import dataset
  from tensorpack.utils import logger
  from tensorpack.utils.gpu import change_gpu
  from tensorpack.utils.argtools import shape2d, shape4d
  from tensorpack.utils.viz import *
label_desc: Use image node_id 3 to create a new ThetaImages object from inherited base classes: ProxyDataFlow, RNGDataFlow with example: obj = ThetaImages(ds)