code: def _conv2d(x, W):
      return tf.nn.conv2d(x, W, strides=[1, 1, 1, 1], padding="SAME")
  
file_path: cleverhans/cleverhans_v3.1.0/examples/madry_lab_challenges/mnist/madry_mnist_model.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from collections import OrderedDict
  import tensorflow
  from cleverhans.model import Model
  from cleverhans.utils import deterministic_dict
  from cleverhans.dataset import Factory, MNIST
label_desc: Use image node_id 6 for calling the MadryMNIST obj's underlying member method code with example usage: obj._conv2d(x, W) and returns: tf