docstr: Regression test for bpo-30570.
docstr_tok: ["Regression","test","for","bpo-30570","."]
code: def test_infinitely_many_bases(self):
      """Regression test for bpo-30570."""
  
      class X:
          def __getattr__(self, attr):
              self.assertEqual(attr, "__bases__")
  
              class A:
                  pass
  
              class B:
                  pass
  
              A.__getattr__ = B.__getattr__ = X.__getattr__
              return (A(), B())
  
      with support.infinite_recursion(25):
          self.assertRaises(RecursionError, issubclass, X(), int)
  
imports: import unittest
  import typing
  from test import support
label_desc: Use image node_id 14 for calling the TestIsInstanceIsSubclass obj's underlying member method code with example usage: obj.test_infinitely_many_bases() and returns: A,  B