code: def test_forward_pass_cuda_memory_bank(self):
      if not torch.cuda.is_available():
          return
  
      reg = CO2Regularizer(memory_bank_size=(4096, 32))
      for bsz in range(1, 20):
          batch_1 = torch.randn((bsz, 32)).cuda()
          batch_2 = torch.randn((bsz, 32)).cuda()
  
          # symmetry
          l1 = reg(batch_1, batch_2)
          self.assertGreater(l1.cpu().item(), 0)
  
file_path: lightly/tests/loss/test_CO2Regularizer.py
imports: import unittest
  import torch
  from lightly.loss.regularizer import CO2Regularizer
label_desc: Use image node_id 4 for calling the TestCO2Regularizer obj's underlying member method code with example usage: obj.test_forward_pass_cuda_memory_bank() without return types