code: def setUpClass(self):
      self.embedding_size = 128
      self.memory_size = 321
  
imports: import unittest
  import torch
  import pytorch_metric_learning.losses
  from pytorch_metric_learning.losses import ContrastiveLoss, CrossBatchMemory, MultiSimilarityLoss, NTXentLoss
  from pytorch_metric_learning.miners import DistanceWeightedMiner, MultiSimilarityMiner, PairMarginMiner, TripletMarginMiner
  from pytorch_metric_learning.utils import loss_and_miner_utils
  from ..None import TEST_DEVICE, TEST_DTYPES
  from ..zzz_testing_utils.testing_utils import angle_to_coord
label_desc: Use image node_id 1 for calling the TestCrossBatchMemory obj's underlying member method code with example usage: obj.setUpClass() without return types