code: def test_empty_sample(self):
      # test sample with empty string and empty list
      self.assertRaises(AttributeError, nli_antonymswap.transform, "")
      self.assertRaises(AttributeError, nli_antonymswap.transform, [])
  
imports: import unittest
  from textflint.input.component.sample.nli_sample import NLISample
  from textflint.generation.transformation.NLI import SwapAnt
label_desc: Use image node_id 3 for calling the TestNliSwapAnt obj's underlying member method code with example usage: obj.test_empty_sample() without return types