code: def test_scale_down(self):
      assert mx.image.scale_down((640, 480), (720, 120)) == (640, 106)
      assert mx.image.scale_down((360, 1000), (480, 500)) == (360, 375)
      assert mx.image.scale_down((300, 400), (0, 0)) == (0, 0)
  
imports: import os
  import mxnet
  import numpy
  import scipy.ndimage
  from mxnet.test_utils import *
  from common import xfail_when_nonstandard_decimal_separator
  import shutil
  import tempfile
  import unittest
  import pytest
label_desc: Use image node_id 9 for calling the TestImage obj's underlying member method code with example usage: obj.test_scale_down() without return types