code: def forward(self, input, target):
      target = target.view(input.shape)
      loss = F.binary_cross_entropy(input, target, reduction="none")
      loss[target == self.masked_with] = 0
      return loss.sum()
  
file_path: pyro/examples/cvae/baseline.py
imports: import copy
  from pathlib import Path
  import numpy
  import torch
  import torch.nn
  import torch.nn.functional
  from tqdm import tqdm
label_desc: Use image node_id 2 for calling the MaskedBCELoss obj's underlying member method code with example usage: obj.forward(input, target) and returns: loss