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."
code: def __init__(self, language="eng"):
      super().__init__()
  
      if language != "eng":
          raise ValueError(f"Language {language} is not available.")
      self.language = language
      self.tokenize = self.processor.tokenize
      self.untokenize = self.processor.inverse_tokenize
  
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 1 to create a new AddDiff object from inherited base classes: ABSATransformation with example: obj = AddDiff(language)