code: def fgsm():
      return attacks.FastGradientMethod
  
file_path: tensor2tensor/tensor2tensor/utils/adv_attack_utils.py
imports: from cleverhans import attacks
  from cleverhans import model
  from cleverhans import utils_tf
  import numpy
  from tensor2tensor.utils import registry
  import tensorflow.compat.v1
label_desc: Use image node_id 1 for calling a global function with example usage: fgsm() and returns: attacks