code: def forward(ctx, i):
      result = i * torch.sigmoid(i)
      ctx.save_for_backward(i)
      return result
  
imports: import re
  import math
  import collections
  from functools import partial
  import torch
  from torch import nn
  from torch.nn import functional
  from torch.utils import model_zoo
label_desc: Use image node_id 1 for calling the SwishImplementation obj's underlying member method code with example usage: obj.forward(ctx, i) and returns: result