Class Descriptor

Lib/test/test_descr.py:4791–4797

        # issue 4230

        class Descriptor(object):
            counter = 0
            def __get__(self, obj, objtype=None):
                def getter(name):
                    self.counter += 1
                    raise AttributeError(name)
                return getter

        descr = Descriptor()
        class A(object):