code: def normal_kl(mu1, lv1, mu2, lv2):
      v1 = torch.exp(lv1)
      v2 = torch.exp(lv2)
      lstd1 = lv1 / 2.0
      lstd2 = lv2 / 2.0
  
      kl = (
          lstd2 - lstd1 + ((v1 + (mu1 - mu2) ** 2.0) / (2.0 * v2)) - 0.5
      )
      return kl
  
imports: import os
  import argparse
  import logging
  import time
  import numpy
  import numpy.random
  import matplotlib
  import matplotlib.pyplot
  import torch
  import torch.nn
  import torch.optim
  import torch.nn.functional
label_desc: Use image node_id 3 for calling a global function with example usage: normal_kl(mu1, lv1, mu2, lv2) and returns: kl