code: def backward(ctx, grad_output):
      input, weight = ctx.saved_tensors
      grad_input = grad_output.mm(weight)
      grad_weight = grad_output.t().mm(input)
      return grad_input, grad_weight
  
imports: import torch
  from torch import nn
  import fused_dense_cuda
  from apex._autocast_utils import _cast_if_autocast_enabled
label_desc: Use image node_id 2 for calling the DenseNoBiasFunc obj's underlying member method code with example usage: obj.backward(ctx, grad_output) and returns: grad_input,  grad_weight