code: def test_invalid_grad_on_execution():
      """Test invalid values for grad on execution raise an error."""
      with pytest.raises(
          ValueError, match=r"grad_on_execution must be True, False,"
      ):
          ExecutionConfig(grad_on_execution="forward")
  
imports: import pytest
  from pennylane.devices import ExecutionConfig
label_desc: Use image node_id 6 for calling a global function with example usage: test_invalid_grad_on_execution() without return types