code: def optimizer(self):
      return tf.train.AdamOptimizer(1e-3)
  
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 4 for calling the Model obj's underlying member method code with example usage: obj.optimizer() and returns: tf