def METHOD_NAME(self):
    class POINT(Structure):
        _fields_ = [("x", c_int), ("y", c_int)]
    class RECT(Structure):
        _fields_ = [("ul", POINT), ("lr", POINT)]
    r = RECT()
    r.ul.x = 0
    r.ul.y = 1
    r.lr.x = 2
    r.lr.y = 3
    self.assertEqual(r._objects, None)
    r = RECT()
    pt = POINT(1, 2)
    r.ul = pt
    self.assertEqual(r._objects, {'0': {}})
    r.ul.x = 22
    r.ul.y = 44
    self.assertEqual(r._objects, {'0': {}})
    r.lr = POINT()
    self.assertEqual(r._objects, {'0': {}, '1': {}})