code: def forward(self, z: Reals[20]) -> Reals[28, 28]:
      h3 = F.relu(self.fc3(z))
      out = torch.sigmoid(self.fc4(h3))
      return out.reshape(out.shape[:-1] + (28, 28))
  
imports: import argparse
  import os
  import typing
  from collections import OrderedDict
  import torch
  import torch.utils.data
  from torch import nn, optim
  from torch.nn import functional
  from torchvision import transforms
  from torchvision.datasets import MNIST
  import funsor
  import funsor.ops
  import funsor.torch.distributions
  from funsor.domains import Bint, Reals
label_desc: Use image node_id 2 for calling the Decoder obj's underlying member method code with example usage: obj.forward(z) and returns: out