code: def categories(self):
      return [
          "a",
          "b",
          "not_a",
          "not_b",
          "a_and_not_b",
          "b_and_not_a",
          "a_and_b",
          "not_a_and_not_b",
      ]
  
file_path: scattertext/scattertext/test/test_semioticSquare.py
imports: from unittest import TestCase
  import pandas
  import numpy
  from scattertext import SemioticSquare
  from scattertext.CorpusFromPandas import CorpusFromPandas
  from scattertext.WhitespaceNLP import whitespace_nlp
  from scattertext.semioticsquare.SemioticSquare import EmptyNeutralCategoriesError
label_desc: Use image node_id 5 for calling the TestSemioticSquare obj's underlying member method code with example usage: obj.categories() and returns: list