class_docstr: A constraint representing a maximum allowed perturbed words.
      We use the lcs div the long of the sentence as the score.
  
  :param ~textflint.input.dataset origin_dataset:
          the dataset of origin sample
  :param ~textflint.input.dataset trans_dataset:
      the dataset of translate sample
  :param str|list fields: the name of the origin field need compare.
  :param bool need_tokens: if we need tokenize the sentence
code: def __init__(
      self, origin_dataset, trans_dataset, fields, need_tokens=True
  ):
      super().__init__(
          origin_dataset, trans_dataset, fields, need_tokens=need_tokens
      )
  
imports: import numpy
  from .validator import Validator
label_desc: Use image node_id 1 to create a new MaxWordsPerturbed object from inherited base classes: Validator with example: obj = MaxWordsPerturbed(origin_dataset, trans_dataset, fields, need_tokens)