code: def test_wrapper_downcast(self):
      a = pass_a(D())
      self.assertEqual("D::g()", a.g())
  
file_path: turicreate/src/external/boost/boost_1_68_0/libs/python/test/polymorphism2.py
imports: import unittest
  import sys
label_desc: Use image node_id 6 for calling the PolymorphTest obj's underlying member method code with example usage: obj.test_wrapper_downcast() without return types