code: def test_invalid_formats(self):
      # test invalid formats
      # these are no corpus, because they do not consists of 2-tuples with
      # the form(int, float).
      potentials = list()
      potentials.append(["human"])
      potentials.append("human")
      potentials.append(["human", "star"])
      potentials.append([1, 2, 3, 4, 5, 5])
      potentials.append([[(0, "string")]])
      for noCorpus in potentials:
          result = utils.is_corpus(noCorpus)
          expected = (False, noCorpus)
          self.assertEqual(expected, result)
  
imports: import logging
  import unittest
  import numpy
  from gensim import utils
  from gensim.test.utils import datapath, get_tmpfile
label_desc: Use image node_id 4 for calling the TestIsCorpus obj's underlying member method code with example usage: obj.test_invalid_formats() without return types