code: def test_replace_variable(self):
      template = """
        def test_fn(a):
          a += 1
          a = 2 * a + 1
          return b
      """
  
      node = templates.replace(template, a="b")[0]
      result, _, _ = loader.load_ast(node)
      self.assertEqual(7, result.test_fn(2))
  
imports: import imp
  import unittest
  import gast
  from nvidia.dali._autograph.pyct import gast_util
  from nvidia.dali._autograph.pyct import loader
  from nvidia.dali._autograph.pyct import parser
  from nvidia.dali._autograph.pyct import qual_names
  from nvidia.dali._autograph.pyct import templates
label_desc: Use image node_id 3 for calling the TemplatesTest obj's underlying member method code with example usage: obj.test_replace_variable() without return types