code: def mixup_criterion(criterion, pred, y_a, y_b, lam):
      return lam * criterion(pred, y_a) + (1 - lam) * criterion(
          pred, y_b
      )
  
imports: import math
  import random
  import numpy
  import torch
  import torch.distributed
  from PIL import Image, ImageEnhance, ImageOps
  from torch.utils.data import Sampler
label_desc: Use image node_id 3 for calling a global function with example usage: mixup_criterion(criterion, pred, y_a, y_b, lam) and returns: unknown