code: def test_attribute_chain_is_maintained(self):
      m = mock.Mock(name="mock_name")
      m.test1.test2.test3.test4
  
      mock.seal(m)
      with self.assertRaises(AttributeError) as cm:
          m.test1.test2.test3.test4.boom
      self.assertIn(
          "mock_name.test1.test2.test3.test4.boom", str(cm.exception)
      )
  
imports: import unittest
  from unittest import mock
label_desc: Use image node_id 17 for calling the TestSealable obj's underlying member method code with example usage: obj.test_attribute_chain_is_maintained() without return types