class_docstr: Add the difference part of aspect to the end of original sentence.
  The difference part is extracted from the training set of SemEval2014
  or user's customization.
  
  Example::
  
      Original sentence: "BEST spicy tuna roll, great asian salad.
      （Target: spicy tuna roll)"
      Transformed sentence: "BEST spicy tuna roll, great asian salad,
      but this small place is packed,
      on a cold day, the seating by the entrance way can be pretty drafty and
      bad service."
docstr: Transform data sample to a list of Sample.
  
  :param ~textflint.input.component.sample.ABSAsample sample: input ABSAsample
  :param int n: the number of transformation, in ABSA-specific transformations n=1
  :param str field:field name
  :param dict extra_text: extra text will be added to the original sentence
  :return list: list of transformed ABSAsample
code: def _transform(
      self, sample, n=1, field="sentence", extra_text=None, **kwargs
  ):
      r"""
      Transform data sample to a list of Sample.
  
      :param ~textflint.input.component.sample.ABSAsample sample: input ABSAsample
      :param int n: the number of transformation, in ABSA-specific transformations n=1
      :param str field:field name
      :param dict extra_text: extra text will be added to the original sentence
      :return list: list of transformed ABSAsample
  
      """
      trans_samples = []
      self.trans_term_list = sample.term_list
      self.terms = sample.terms
      self.term_list = sample.term_list
      self.sentence = sample.sentence.text
      if sample.trans_id is None:
          self.trans_id = [idx for idx in self.terms]
      else:
          self.trans_id = [sample.trans_id]
      all_term = [self.term_list[idx]["term"] for idx in self.term_list]
  
      for term_id in self.trans_id:
          trans_sample = sample.clone(sample)
          polarity = self.term_list[term_id]["polarity"]
          if polarity == "positive":
              add_text = extra_text["negative"]
          elif polarity == "negative":
              add_text = extra_text["positive"]
          else:
              add_text = extra_text["neutral"]
  
          add_sentence = self._get_add_sentence(add_text, all_term)
          trans_sentence = self._concatenate_sentence(add_sentence)
          trans_sample.update_sentence(trans_sentence)
          trans_sample.trans_id = term_id
          trans_samples.append(trans_sample)
  
      return trans_samples
  
file_path: textflint/textflint/generation/transformation/ABSA/add_diff.py
imports: import random
  import string
  from .absa_transformation import ABSATransformation
label_desc: Use image node_id 3 for calling the AddDiff obj's underlying member method code with example usage: obj._transform(sample, n, field, extra_text) and returns: trans_samples