code: def test_epoch(self):
      hparams = {
          "p": None,
          "num_steps": None,
          "batch_size": 10,
          "workers": 0,
      }
  
      module = TestSSLModule(self.al_dataset, **hparams)
      trainer = Trainer(
          max_epochs=1,
          num_sanity_val_steps=0,
          logger=False,
          enable_checkpointing=False,
      )
      trainer.fit(module)
  
      assert len(module.labeled_data) == len(module.unlabeled_data)
      assert torch.all(torch.tensor(module.labeled_data) % 2 == 0)
      assert torch.all(torch.tensor(module.unlabeled_data) % 2 != 0)
  
imports: import unittest
  from argparse import Namespace
  import torch
  from baal.active import ActiveLearningDataset
  from pytorch_lightning import Trainer
  from baal.utils.ssl_module import SSLModule
  from torch import nn
  from torch.utils.data import ConcatDataset
  from tests.utils.ssl_iterator_test import SSLTestDataset
label_desc: Use image node_id 2 for calling the SSLModuleTest obj's underlying member method code with example usage: obj.test_epoch() without return types