code: def test_adding_default_policies_preserves_default_factory(self):
      newpolicy = email.policy.default + email.policy.strict
      self.assertEqual(
          newpolicy.header_factory,
          email.policy.EmailPolicy.header_factory,
      )
      self.assertEqual(newpolicy.__dict__, {"raise_on_defect": True})
  
imports: import io
  import types
  import textwrap
  import unittest
  import email.errors
  import email.policy
  import email.parser
  import email.generator
  import email.message
  from email import headerregistry
label_desc: Use image node_id 18 for calling the PolicyAPITests obj's underlying member method code with example usage: obj.test_adding_default_policies_preserves_default_factory() without return types