code: def update(self, loss, output, target):
      acc1, acc5 = accuracy(output, target, topk=(1, 5))
      self.losses.update(loss.item(), output.size(0))
      self.top1.update(acc1[0], output.size(0))
      self.top5.update(acc5[0], output.size(0))
  
imports: import collections
  import torch
  from torch import Tensor
  import torch.nn
  import torch.backends.cudnn
  import subprocess
  import os
  import time
  import shutil
  from datetime import datetime
  import torch.optim
  from torch.optim import lr_scheduler
  import sys
  import models
  import numpy
  import torch.nn
  import math
label_desc: Use image node_id 2 for calling the LossTracker obj's underlying member method code with example usage: obj.update(loss, output, target) without return types