code: def test_adapt_subtype_3(self):
      class A:
          pass
  
      class B(A):
          pass
  
      register_adapter(A, lambda a: AsIs("a"))
      self.assertEqual(b"a", adapt(B()).getquoted())
  
imports: import string
  import ctypes
  import decimal
  import datetime
  import platform
  from .None import testutils
  import unittest
  from .testutils import ConnectingTestCase, restore_types
  from .testutils import skip_if_crdb
  import psycopg2
  from psycopg2.extensions import AsIs, adapt, register_adapter
label_desc: Use image node_id 3 for calling the AdaptSubclassTest obj's underlying member method code with example usage: obj.test_adapt_subtype_3() without return types