code: def test_transformation(self):
      sent1 = (
          "To whom did the Virgin Mary allegedly appear in "
          "1858 in Lourdes France?"
      )
      data_sample = SASample({"x": sent1, "y": "negative"})
      trans = BackTrans(device="cpu")
      x = trans.transform(data_sample, n=1)
      self.assertEqual(
          "To whom did the Virgin Mary allegedly appear "
          "in Lourdes, France, in 1858?",
          x[0].get_text("x"),
      )
      self.assertEqual("negative", x[0].get_value("y"))
  
imports: import unittest
  from textflint.input.component.sample import SASample
  from textflint.generation.transformation.UT.back_trans import BackTrans
label_desc: Use image node_id 1 for calling the TestBackTrans obj's underlying member method code with example usage: obj.test_transformation() without return types