code: def test_forward(self) -> None:
      torch.manual_seed(0)
      for num_target_views in range(1, 4):
          with self.subTest(num_views=num_target_views):
              criterion = MSNLoss()
              anchors = torch.rand((8 * num_target_views, 10))
              targets = torch.rand((8, 10))
              prototypes = torch.rand((4, 10), requires_grad=True)
              criterion(anchors, targets, prototypes)
  
imports: import unittest
  from unittest import TestCase
  import pytest
  import torch
  import torch.nn.functional
  from pytest_mock import MockerFixture
  from torch import distributed
  from torch import nn
  from torch.optim import SGD
  from lightly.loss import msn_loss
  from lightly.loss.msn_loss import MSNLoss
  from lightly.models.modules.heads import MSNProjectionHead
label_desc: Use image node_id 8 for calling the TestMSNLossUnitTest obj's underlying member method code with example usage: obj.test_forward() without return types