class_docstr: Abstract base class for preprocessing defences.
  
  By default, the gradient is estimated using BPDA with the identity function.
      To modify, override `estimate_gradient`
code: def _check_params(self) -> None:  # pragma: no cover
      pass
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import abc
  from typing import List, Optional, Tuple, Any, TYPE_CHECKING
  import numpy
  from art import config
label_desc: Use image node_id 9 for calling the Preprocessor obj's underlying member method code with example usage: obj._check_params() without return types