code: def __len__(self):
      return len(self.original)
  
file_path: pyro/examples/cvae/mnist.py
imports: import numpy
  import torch
  from torch.utils.data import DataLoader, Dataset
  from torchvision.transforms import Compose, functional
  from pyro.contrib.examples.util import MNIST
label_desc: Use image node_id 2 for calling the CVAEMNIST obj's underlying member method code with example usage: obj.__len__() and returns: len