code: def _sum(x: List[Tensor]) -> Tensor:
      res = x[0]
      for i in x[1:]:
          res = res + i
      return res
  
imports: import math
  import warnings
  from collections import OrderedDict
  from typing import Dict, List, Tuple, Optional, Union
  import torch
  from torch import nn, Tensor
  from .None import det_utils
  from .anchor_utils import AnchorsGenerator
  from .None import boxes
  from .losses import sigmoid_focal_loss
  from .transform import GeneralizedRCNNTransform
label_desc: Use image node_id 1 for calling a global function with example usage: _sum(x) and returns: res