code: def backward(ctx, grad_output):
      return grad_output * ctx.scale, None
  
imports: from typing import List
  import torch
  from torch import nn
  from torch.autograd.function import Function
  from detectron2.config import configurable
  from detectron2.layers import ShapeSpec
  from detectron2.structures import Boxes, Instances, pairwise_iou
  from detectron2.utils.events import get_event_storage
  from ..box_regression import Box2BoxTransform
  from ..matcher import Matcher
  from ..poolers import ROIPooler
  from .box_head import build_box_head
  from .fast_rcnn import FastRCNNOutputLayers, fast_rcnn_inference
  from .roi_heads import ROI_HEADS_REGISTRY, StandardROIHeads
label_desc: Use image node_id 2 for calling the _ScaleGradient obj's underlying member method code with example usage: obj.backward(ctx, grad_output) and returns: unknown,  None