code: def update_prior(self):
      self.prior.encoder_old.load_state_dict(
          deepcopy(self.encoder.state_dict())
      )
  
imports: import numpy
  from copy import deepcopy
  import torch
  import torch.nn
  import torch.nn.functional
label_desc: Use image node_id 4 for calling the VAE obj's underlying member method code with example usage: obj.update_prior() without return types