code: def on_train_end(self, trainer, pl_module):
      for lightning_grad, mmf_grad in zip(
          self.lightning_grads, self.mmf_grads
      ):
          self.assertAlmostEqual(lightning_grad, mmf_grad, places=6)
  
file_path: mmf/tests/trainers/lightning/test_grad_clipping.py
imports: import unittest
  from unittest.mock import MagicMock, patch
  import torch
  from mmf.utils.general import clip_gradients
  from pytorch_lightning.callbacks.base import Callback
  from tests.trainers.test_utils import get_config_with_defaults, get_lightning_trainer, get_mmf_trainer
label_desc: Use image node_id 4 for calling the TestLightningTrainerGradClipping obj's underlying member method code with example usage: obj.on_train_end(trainer, pl_module) without return types