class_docstr: Test the user interface of the op_transform, and ensure it applies
  and works well for all combinations of inputs and styles
docstr: Test that a transform can be applied to a quantum function
  that contains a single operation
docstr_tok: ["Test","that","a","transform","can","be","applied","to","a","quantum","function","that","contains","a","single","operation"]
code: def test_single_operator_qfunc(self, mocker):
      """Test that a transform can be applied to a quantum function
      that contains a single operation"""
      spy = mocker.spy(qml.op_transform, "_make_tape")
  
      @qml.op_transform
      def my_transform(op):
          return op.name
  
      # pylint:disable=assignment-from-no-return
      res = my_transform(qml.CRX)(0.5, wires=[0, "a"])
      assert res == "CRX"
  
      # check default wire order
      assert spy.spy_return[1].tolist() == [0, "a"]
  
imports: import pytest
  import pennylane
  from pennylane import numpy
  from pennylane.transforms.op_transforms import OperationTransformError
label_desc: Use image node_id 2 for calling the TestUI obj's underlying member method code with example usage: obj.test_single_operator_qfunc(mocker) and returns: op