code: def test_existing_attributes_allowed_after_seal(self):
      m = mock.Mock()
  
      m.test.return_value = 3
  
      mock.seal(m)
      self.assertEqual(m.test(), 3)
  
imports: import unittest
  from unittest import mock
label_desc: Use image node_id 6 for calling the TestSealable obj's underlying member method code with example usage: obj.test_existing_attributes_allowed_after_seal() without return types