code: def test_closure(self):
      b = 1
  
      def f(a):
          return a + b
  
      tr = TestTranspiler()
      f, _, _ = tr.transform(f, None)
  
      self.assertEqual(f(1), 0)
      b = 2
      self.assertEqual(f(1), -1)
  
imports: import threading
  import gast
  from tensorflow.python.autograph.pyct import transformer
  from tensorflow.python.autograph.pyct import transpiler
  from tensorflow.python.platform import test
label_desc: Use image node_id 2 for calling the PyToPyTest obj's underlying member method code with example usage: obj.test_closure() and returns: unknown