code: def test_run_config():
      with pytest.raises(ValueError):
          DummyTrainer(run_config="invalid")
  
      with pytest.raises(ValueError):
          DummyTrainer(run_config=False)
  
      with pytest.raises(ValueError):
          DummyTrainer(run_config=True)
  
      with pytest.raises(ValueError):
          DummyTrainer(run_config={})
  
      # Succeed
      DummyTrainer(run_config=None)
  
      # Succeed
      DummyTrainer(run_config=ray.train.RunConfig())
  
imports: import pytest
  import ray
  from ray.train import Checkpoint, CheckpointConfig, ScalingConfig
  from ray.air._internal.config import ensure_only_allowed_dataclass_keys_updated
  from ray.data.preprocessor import Preprocessor
  from ray.train.trainer import BaseTrainer
label_desc: Use image node_id 1 for calling a global function with example usage: test_run_config() without return types