class_docstr: Filter samples based on a group of phrases
  
  for example, with phrase_name = 'question'::
  
      sample 1: "Who is Jack.", score: 1
      sample 2: "I am Jack.", score: 0
code: def __repr__(self):
      return "PhraseSubPopulation" + "-" + self.phrase_name
  
file_path: textflint/textflint/generation/subpopulation/UTCN/phrase.py
imports: from flashtext import KeywordProcessor
  from ..subpopulation import SubPopulation
  from ....common.settings import NEGATION, QUESTION
label_desc: Use image node_id 2 for calling the PhraseSubPopulation obj's underlying member method code with example usage: obj.__repr__() and returns: unknown