code: def test_exc_mutable_var_fail():
      def mutable_var_check(waitall=False):
          a, b = mx.nd.random_normal(0, -1, (2, 2)).copyto(
              default_device()
          )
          a = mx.nd.dot(a, a)
          if waitall:
              mx.nd.waitall()
          else:
              a.asnumpy()
  
      pytest.raises(MXNetError, mutable_var_check, waitall=False)
      pytest.raises(MXNetError, mutable_var_check, waitall=True)
  
file_path: mxnet/tests/python/unittest/test_exc_handling.py
imports: import os
  import mxnet
  import numpy
  from mxnet import gluon
  from mxnet.gluon import nn
  from mxnet.base import MXNetError
  from mxnet.test_utils import assert_exception, default_device, set_default_device, use_np
  import pytest
label_desc: Use image node_id 5 for calling a global function with example usage: test_exc_mutable_var_fail() without return types