code: def on_train_epoch_end(self):
      assert torch.tensor([0.0]).dtype == torch.float32
  
imports: import pickle
  from unittest.mock import MagicMock
  import pytest
  import torch
  from lightning.pytorch import Trainer
  from lightning.pytorch.demos.boring_classes import BoringModel, RandomDataset
  from lightning.pytorch.plugins.precision.double import DoublePrecision
  from torch.utils.data import DataLoader, Dataset
  from tests_pytorch.helpers.runif import RunIf
label_desc: Use image node_id 2 for calling the DoublePrecisionBoringModel obj's underlying member method code with example usage: obj.on_train_epoch_end() without return types