code: def test_label(self):
      # SmAntonymSwap will change some word to its opposite
      # meaning, which leads y to '0'
      trans = sm_antonymswap.transform(sample1)
      self.assertEqual("0", trans[0].y.field_value)
  
imports: import unittest
  from textflint.input.component.sample.sm_sample import SMSample
  from textflint.generation.transformation.SM import SwapWord
label_desc: Use image node_id 2 for calling the TestSwapWord obj's underlying member method code with example usage: obj.test_label() without return types