如何使用tensorflow sess更改Cleverhans 'test_imagenet_attacks.py‘？

import tensorflow as tf
from cleverhans.utils_tf import model_eval
from cleverhans.attacks import FastGradientMethod

sess = tf.Session()
# 加载模型并创建一个新的图
with sess.as_default():
    saver = tf.train.import_meta_graph('path_to_model.meta')
    saver.restore(sess, tf.train.latest_checkpoint('path_to_checkpoint'))
    graph = tf.get_default_graph()

# 获取输入和输出张量
x = graph.get_tensor_by_name('input:0')
y = graph.get_tensor_by_name('output:0')

# 创建一个占位符用于传递测试数据
x_test = tf.placeholder(tf.float32, shape=(None, 224, 224, 3))
y_test = tf.placeholder(tf.float32, shape=(None, 1000))

# 创建FastGradientMethod攻击对象
fgsm = FastGradientMethod(model=model, sess=sess)

# 生成对抗样本
x_adv = fgsm.generate(x_test)

# 运行攻击
adv_samples = sess.run(x_adv, feed_dict={x_test: test_images})

# 评估模型性能
accuracy = model_eval(sess, x, y, adv_samples, test_labels)
print("对抗样本的准确率：", accuracy)