code: def test_transformation(self):
      import random
  
      random.seed(100)
      sent1 = "那只敏捷的棕色狐狸跳过了那只懒惰的狗。"
      data_sample = UTCnSample({"x": sent1, "y": "negative"})
      trans = BackTrans(device="cpu")
      x = trans.transform(data_sample, n=1)
      self.assertEqual("敏捷的棕色狐狸跳过懒狗", x[0].get_text("x"))
  
imports: import unittest
  from textflint.input.component.sample import UTCnSample
  from textflint.generation.transformation.UTCN 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