code: def test_attribute(self):
      class TestClass(object):
          def __init__(self):
              self.v = 1
  
          def __add__(self, other):
              self.v += other
              return self
  
      def f(l):
          return l.v
  
      tc = TestClass()
      tr = self._transform_with_test_ld(f)
  
      self.assertEqual(tr(tc), 2)
  
file_path: DALI/dali/test/python/autograph/converters/test_variables.py
imports: from nvidia.dali._autograph.converters import variables
  from nvidia.dali._autograph.core import converter_testing
label_desc: Use image node_id 12 for calling the VariablesTest obj's underlying member method code with example usage: obj.test_attribute() and returns: l, self