code: def forward(self, x):
      assert isinstance(x, dy.Expression)
      mu, logvar = self.encode(x)
      z = self.reparameterize(mu, logvar)
      return self.decode(z), mu, logvar
  
file_path: dynet/examples/variational-autoencoder/basic-image-recon/vae.py
imports: from __future__ import print_function
  from utils import load_mnist, make_grid, pre_pillow_float_img_process, save_image
  import numpy
  import argparse
  import dynet
  import os
  import time
label_desc: Use image node_id 5 for calling the VAE obj's underlying member method code with example usage: obj.forward(x) and returns: self,  mu,  logvar