code: def test_function_with_single_arg(self):
      def f(f, a):
          return f(a) + 20
  
      tr, mock = self._transform_with_mock(f)
  
      self.assertEqual(tr(lambda a: a, 1), 21)
      self.assertListEqual(mock.calls, [((1,), None)])
  
imports: import imp
  from nvidia.dali._autograph.converters import call_trees
  from nvidia.dali._autograph.converters import functions
  from nvidia.dali._autograph.core import converter_testing
label_desc: Use image node_id 6 for calling the CallTreesTest obj's underlying member method code with example usage: obj.test_function_with_single_arg() and returns: unknown