class_docstr: A constraint on edit distance (Levenshtein Distance).
  We use the Levenshtein Distance div the long of the sentence as 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.
code: def __init__(self, origin_dataset, trans_dataset, fields):
      super().__init__(origin_dataset, trans_dataset, fields)
  
imports: import editdistance
  from .validator import Validator
label_desc: Use image node_id 1 to create a new EditDistance object from inherited base classes: Validator with example: obj = EditDistance(origin_dataset, trans_dataset, fields)