code: def test_multiple_waitalls():
      caught = False
      try:
          a = mx.nd.random.normal(0, -1, (2, 2)).copyto(
              default_device()
          )
          mx.nd.waitall()
      except MXNetError:
          caught = True
      assert caught, "No exception thrown"
      mx.nd.waitall()
  
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 6 for calling a global function with example usage: test_multiple_waitalls() without return types