code: def test_op_transform_is_deprecated():
      """Test that the op_transform class is deprecated."""
  
      def func(op):
          return op
  
      with pytest.warns(
          UserWarning,
          match="Use of `op_transform` to create a custom transform is deprecated",
      ):
          _ = qml.op_transform(func)
  
imports: import pytest
  import pennylane
  from pennylane import numpy
  from pennylane.transforms.op_transforms import OperationTransformError
label_desc: Use image node_id 4 for calling a global function with example usage: test_op_transform_is_deprecated() and returns: op