code: def test_replace_code_block(self):
      template = """
        def test_fn(a):
          block
          return a
      """
  
      class ShouldBeReplaced(object):
          pass
  
      node = templates.replace(
          template,
          block=[
              gast.Assign(
                  targets=[
                      gast.Name(
                          "a",
                          ctx=ShouldBeReplaced,
                          annotation=None,
                          type_comment=None,
                      )
                  ],
                  value=gast.BinOp(
                      gast.Name(
                          "a",
                          ctx=ShouldBeReplaced,
                          annotation=None,
                          type_comment=None,
                      ),
                      gast.Add(),
                      gast.Constant(1, kind=None),
                  ),
              ),
          ]
          * 2,
      )[0]
      result, _, _ = loader.load_ast(node)
      self.assertEqual(3, result.test_fn(1))
  
imports: import types
  from absl.testing import parameterized
  import gast
  from tensorflow.python.autograph.pyct import loader
  from tensorflow.python.autograph.pyct import parser
  from tensorflow.python.autograph.pyct import qual_names
  from tensorflow.python.autograph.pyct import templates
  from tensorflow.python.platform import test
label_desc: Use image node_id 5 for calling the TemplatesTest obj's underlying member method code with example usage: obj.test_replace_code_block() without return types