class_docstr: Transformation that leverage pre-defined spelling mistake dictionary to
  simulate spelling mistake.
  
  https://arxiv.org/ftp/arxiv/papers/1812/1812.04718.pdf
code: def skip_aug(self, tokens, mask, **kwargs):
      pre_skipped_idxes = self.pre_skip_aug(tokens, mask)
      results = []
  
      for token_idx in pre_skipped_idxes:
          # Some words do not exit. It will be excluded in lucky draw.
          token = tokens[token_idx]
          if (
              token in self.rules.rules
              and len(self.rules.rules[token]) > 0
          ):
              results.append(token_idx)
  
      return results
  
file_path: textflint/textflint/generation/transformation/UT/spelling_error.py
imports: from ...transformation import WordSubstitute
  from ....common.settings import SPELLING_ERROR_DIC
  from ....common.utils.install import download_if_needed
label_desc: Use image node_id 3 for calling the SpellingError obj's underlying member method code with example usage: obj.skip_aug(tokens, mask) and returns: results