code: def test_forward_pass(self):
      loss = SymNegCosineSimilarityLoss()
      for bsz in range(1, 20):
          z0 = torch.randn((bsz, 32))
          p0 = torch.randn((bsz, 32))
          z1 = torch.randn((bsz, 32))
          p1 = torch.randn((bsz, 32))
  
          # symmetry
          l1 = loss((z0, p0), (z1, p1))
          l2 = loss((z1, p1), (z0, p0))
          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 1 for calling the TestSymNegCosineSimilarityLoss obj's underlying member method code with example usage: obj.test_forward_pass() without return types