code: def test_passing_env_variables_only():
      """Testing overwriting trainer arguments."""
      trainer = Trainer()
      assert trainer.logger is None
      assert trainer.max_steps == 7
  
file_path: pytorch-lightning/tests/tests_pytorch/trainer/flags/test_env_vars.py
imports: import os
  from unittest import mock
  from lightning.pytorch import Trainer
  from lightning.pytorch.demos.boring_classes import BoringModel
label_desc: Use image node_id 2 for calling a global function with example usage: test_passing_env_variables_only() without return types