code: def test_amp_precision_optimizer_step_with_scaler():
      precision = MixedPrecision(precision="16-mixed", device="cuda")
      precision.scaler = Mock()
      optimizer = Mock()
  
      precision.optimizer_step(optimizer, keyword="arg")
      precision.scaler.step.assert_called_once_with(
          optimizer, keyword="arg"
      )
      precision.scaler.update.assert_called_once()
  
file_path: pytorch-lightning/tests/tests_fabric/plugins/precision/test_amp.py
imports: import re
  from unittest.mock import Mock
  import pytest
  import torch
  from lightning.fabric.plugins.precision.amp import MixedPrecision
label_desc: Use image node_id 5 for calling a global function with example usage: test_amp_precision_optimizer_step_with_scaler() without return types