code: def test_imdecode_invalid_image(self):
      with pytest.raises(mx.base.MXNetError):
          image = mx.image.imdecode(b"clearly not image content")
  
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 8 for calling the TestImage obj's underlying member method code with example usage: obj.test_imdecode_invalid_image() without return types