code: def optimizer(self):
      return tf.train.AdamOptimizer(2e-4, beta1=0.5, epsilon=1e-3)
  
file_path: tensorpack/examples/GAN/ConditionalGAN-mnist.py
imports: import argparse
  import numpy
  import os
  import cv2
  import tensorflow
  from tensorpack import *
  from tensorpack.dataflow import dataset
  from tensorpack.tfutils.scope_utils import auto_reuse_variable_scope
  from tensorpack.utils.viz import interactive_imshow, stack_patches
  from GAN import GANModelDesc, GANTrainer, RandomZData
label_desc: Use image node_id 5 for calling the Model obj's underlying member method code with example usage: obj.optimizer() and returns: tf