class_docstr: Implementation of the attack from Hirano and Takemoto (2019). Computes a fixed perturbation to be applied to all
  future inputs. To this end, it can use any adversarial attack method.
  
  | Paper link: https://arxiv.org/abs/1911.06502
class_docstr_tok: ["Implementation","of","the","attack","from","Hirano","and","Takemoto","(","2019",")",".","Computes","a","fixed","perturbation","to","be","applied","to","all","future","inputs",".","To","this","end",",","it","can","use","any","adversarial","attack","method",".","|","Paper","link",":","https",":","\/\/arxiv.org\/abs\/1911.06502"]
docstr: Get an attack object from its name.
  
  :param a_name: attack name.
  :param params: attack params.
  :return: attack object
docstr_tok: ["Get","an","attack","object","from","its","name",".",":","param","a_name",":","attack","name",".",":","param","params",":","attack","params",".",":","return",":","attack","object"]
code: def _get_attack(
      self, a_name: str, params: Optional[Dict[str, Any]] = None
  ) -> EvasionAttack:
      """
      Get an attack object from its name.
  
      :param a_name: attack name.
      :param params: attack params.
      :return: attack object
      """
      try:
          attack_class = self._get_class(self.attacks_dict[a_name])
          a_instance = attack_class(self.estimator)  # type: ignore
  
          if params:
              a_instance.set_params(**params)
  
          return a_instance
  
      except KeyError:
          raise NotImplementedError(
              f"{a_name} attack not supported"
          ) from KeyError
  
file_path: adversarial-robustness-toolbox/art/attacks/evasion/targeted_universal_perturbation.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import logging
  import random
  import types
  from typing import Any, Dict, Optional, Union, TYPE_CHECKING
  import numpy
  from art.attacks.attack import EvasionAttack
  from art.estimators.estimator import BaseEstimator
  from art.estimators.classification.classifier import ClassifierMixin
  from art.utils import projection
label_desc: Use image node_id 4 for calling the TargetedUniversalPerturbation obj's underlying member method code with example usage: obj._get_attack(a_name, params) and returns: a_instance