code: def test_matmul_py3(self):
      code = dedent(
          """
          def fn(a, b):
              return a @ b
          """
      )
  
      with tempfile.TemporaryDirectory() as tmp_dir:
          script_path = os.path.join(tmp_dir, "script.py")
          with open(script_path, "w") as f:
              f.write(code)
          fn = get_fn("test_matmul_py3", script_path)
  
          a = torch.rand(4, 3, requires_grad=True)
          b = torch.rand(3, 2, requires_grad=True)
          self.checkScript(fn, (a, b), optimize=True)
  
imports: import os
  import sys
  import tempfile
  import random
  from textwrap import dedent
  import torch
  from torch.testing._internal.jit_utils import JitTestCase, execWrapper
label_desc: Use image node_id 3 for calling the TestPythonBuiltinOP obj's underlying member method code with example usage: obj.test_matmul_py3() without return types