class_docstr: Transforms an input by replacing its words with double denial forms.
  
  Example::
  
      ori: The leading actor is good
      trans: The leading actor is not bad
docstr: get words that can be converted to a double denial form
  
  :param list tokens: tokenized words
  :return list indices:  indices of tokens that should be replaced
  :return list double_denial_words: The new words that correspond to
      indices and is used to replace them
docstr_tok: ["get","words","that","can","be","converted","to","a","double","denial","form",":","param","list","tokens",":","tokenized","words",":","return","list","indices",":","indices","of","tokens","that","should","be","replaced",":","return","list","double_denial_words",":","The","new","words","that","correspond","to","indices","and","is","used","to","replace","them"]
code: def _get_double_denial_info(self, tokens):
      r"""
      get words that can be converted to a double denial form
  
      :param list tokens: tokenized words
      :return list indices:  indices of tokens that should be replaced
      :return list double_denial_words: The new words that correspond to
          indices and is used to replace them
  
      """
      if tokens is str:
          tokens = [tokens]
  
      tokens = [
          token.lower() for token in tokens if isinstance(token, str)
      ]
      indices = []
      double_denial_words = []
  
      for polarity_word in self.polarity_dict.keys():
          polarity_word_cnt = tokens.count(polarity_word)
          current_index = -1
          for i in range(polarity_word_cnt):
              # TODO
              try:
                  current_index = tokens.index(
                      polarity_word, current_index + 1
                  )
                  indices.append(current_index)
                  double_denial_words.append(
                      self.polarity_dict[polarity_word]
                  )
              except ValueError:
                  pass
  
      return indices, double_denial_words
  
file_path: textflint/textflint/generation/transformation/SA/double_denial.py
imports: from ..transformation import Transformation
  from ....common.settings import SA_DOUBLE_DENIAL_DICT
label_desc: Use image node_id 4 for calling the DoubleDenial obj's underlying member method code with example usage: obj._get_double_denial_info(tokens) and returns: indices,  double_denial_words