code: def sum(self, name: Optional[str] = None) -> "Variable":
      return operator_sum(self, name)
  
imports: from typing import Callable, Dict, List, NamedTuple, Optional
  import torch
  import torch._dynamo
  from torch._dynamo.test_case import run_tests, TestCase
  from torch._dynamo.testing import CompileCounter, same
label_desc: Use image node_id 6 for calling the Variable obj's underlying member method code with example usage: obj.sum(name) and returns: operator_sum