code: def test_empty_output(self):
      miner = PairMarginMiner(0, 1)
      batch_size = 32
      for dtype in TEST_DTYPES:
          embeddings = (
              torch.randn(batch_size, 64).type(dtype).to(TEST_DEVICE)
          )
          labels = torch.arange(batch_size)
          a, p, _, _ = miner(embeddings, labels)
          self.assertTrue(len(a) == 0)
          self.assertTrue(len(p) == 0)
  
file_path: pytorch-metric-learning/tests/miners/test_pair_margin_miner.py
imports: import unittest
  import torch
  from pytorch_metric_learning.distances import CosineSimilarity, LpDistance
  from pytorch_metric_learning.miners import PairMarginMiner
  from ..None import TEST_DEVICE, TEST_DTYPES, WITH_COLLECT_STATS
  from ..zzz_testing_utils import testing_utils
  from ..zzz_testing_utils.testing_utils import angle_to_coord
label_desc: Use image node_id 2 for calling the TestPairMarginMiner obj's underlying member method code with example usage: obj.test_empty_output() without return types