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 __repr__(self):
      return "AddDiff"
  
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 2 for calling the AddDiff obj's underlying member method code with example usage: obj.__repr__() and returns: str