docstr: Returns adversarial examples for the tensor.
  :param x: input tensor.
  :return: a numpy tensor with the adversarial example.
docstr_tok: ["Returns","adversarial","examples","for","the","tensor",".",":","param","x",":","input","tensor",".",":","return",":","a","numpy","tensor","with","the","adversarial","example","."]
code: def attack(self, x):
      """
      Returns adversarial examples for the tensor.
      :param x: input tensor.
      :return: a numpy tensor with the adversarial example.
      """
      adv_ex = np.zeros_like(x)
      for i in range(0, len(x), self.batch_size):
          adv_ex[i : i + self.batch_size] = self._attack(
              x[i : i + self.batch_size]
          ).numpy()
  
      return adv_ex
  
file_path: cleverhans/cleverhans/tf2/attacks/carlini_wagner_l2.py
imports: import numpy
  import tensorflow
  from cleverhans.tf2.utils import get_or_guess_labels, set_with_mask
label_desc: Use image node_id 2 for calling the CarliniWagnerL2 obj's underlying member method code with example usage: obj.attack(x) and returns: adv_ex