code: def test_neg_cosine_simililarity(self):
      loss = SymNegCosineSimilarityLoss()
      for bsz in range(1, 20):
          x = torch.randn((bsz, 32))
          y = torch.randn((bsz, 32))
  
          # symmetry
          l1 = loss._neg_cosine_simililarity(x, y)
          l2 = loss._neg_cosine_simililarity(y, x)
          self.assertAlmostEqual((l1 - l2).pow(2).item(), 0.0)
  
file_path: lightly/tests/loss/test_SymNegCosineSimilarityLoss.py
imports: import unittest
  import torch
  from lightly.loss import SymNegCosineSimilarityLoss
label_desc: Use image node_id 3 for calling the TestSymNegCosineSimilarityLoss obj's underlying member method code with example usage: obj.test_neg_cosine_simililarity() without return types