code: def get_decoder_params(self):
      return chain(
          self.PPN.parameters(),
          self.FPN.parameters(),
          self.head.parameters(),
      )
  
imports: import torch
  import logging
  import torch.nn
  import torch.nn.functional
  from torchvision import models
  from itertools import chain
  import numpy
  from collections import OrderedDict
label_desc: Use image node_id 4 for calling the UperNet obj's underlying member method code with example usage: obj.get_decoder_params() and returns: chain