code: def test_label(self):
      # SmNumWord will change some thing about number,
      # which leads contradiction label
      trans = sm_numword.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 SwapNum
label_desc: Use image node_id 2 for calling the TestSwapNum obj's underlying member method code with example usage: obj.test_label() without return types