code: def forward(ctx, x1, out):
      return out
  
imports: from enum import Enum
  import math
  import numpy
  import torch
  import warnings
  from .event_handling import combine_event_functions
label_desc: Use image node_id 1 for calling the _StitchGradient obj's underlying member method code with example usage: obj.forward(ctx, x1, out) and returns: out