code: def test_mangling(self):
      class X:
          def f(self, *, __a=42):
              return __a
  
      self.assertEqual(X().f(), 42)
  
imports: import unittest
label_desc: Use image node_id 11 for calling the KeywordOnlyArgTestCase obj's underlying member method code with example usage: obj.test_mangling() and returns: __a