code: def test_search_index(self):
      expected = np.array([7, 9])
      self.assertIsInstance(self.corpus, CorpusDF)
      returned = self.corpus.search_index("speak up")
      np.testing.assert_array_equal(expected, returned)
  
file_path: scattertext/scattertext/test/test_corpusFromPandas.py
imports: from unittest import TestCase
  import numpy
  import pandas
  from scattertext import chinese_nlp, CorpusDF
  from scattertext import whitespace_nlp
  from scattertext.CorpusFromPandas import CorpusFromPandas
label_desc: Use image node_id 6 for calling the TestCorpusFromPandas obj's underlying member method code with example usage: obj.test_search_index() without return types