'__deepcopy__() should copy all attributes properly (#25085).'

def test_deepcopy(self):

    widget = Select()
    obj = copy.deepcopy(widget)
    self.assertIsNot(widget, obj)
    self.assertEqual(widget.choices, obj.choices)
    self.assertIsNot(widget.choices, obj.choices)
    self.assertEqual(widget.attrs, obj.attrs)
    self.assertIsNot(widget.attrs, obj.attrs)
