code: def test_optimizer_backward_compat():
      optimizer = mx.optimizer.SGD()
      delattr(optimizer, "allow_np_array")
      updater = mx.optimizer.Updater(optimizer)
      updater(0, np.ones((0, 0)), np.zeros((0, 0)))
  
imports: from __future__ import absolute_import
  from __future__ import division
  import os
  from uuid import uuid4
  import numpy
  import mxnet
  from mxnet import gluon, autograd, np, npx
  from mxnet.test_utils import use_np, assert_almost_equal, check_gluon_hybridize_consistency, assert_allclose
  from mxnet.gluon import nn
  from mxnet.base import MXNetError
  import random
  import pytest
label_desc: Use image node_id 3 for calling a global function with example usage: test_optimizer_backward_compat() without return types