code: def test_del_default(self):
      self.check_del(null=False, ptds=False)
  
imports: import gc
  import threading
  import unittest
  import pytest
  import cupy
  from cupy._creation import from_data
  from cupy import cuda
  from cupy import testing
label_desc: Use image node_id 7 for calling the TestStream obj's underlying member method code with example usage: obj.test_del_default() without return types