code: def test_asnumpy_blocking(self, blocking):
      prefactor = 4
      a = cupy.random.random(
          prefactor * 128 * 1024 * 1024, dtype=cupy.float64
      )
      cupy.cuda.Device().synchronize()
  
      # Idea: perform D2H copy on a nonblocking stream, during which we try
      # to "corrupt" the host data via NumPy operation. If the copy is
      # properly ordered, corruption would not be possible. Here we craft a
      # problem size and use pinned memory to ensure the failure can be
      # always triggered. (The CUDART API reference ("API synchronization
      # behavior") states that copying between device and pageable memory
      # "might be" synchronous, whereas between device and page-locked
      # memory "should be" fully asynchronous.)
      s = cupy.cuda.Stream(non_blocking=True)
      with s:
          c = cupyx.empty_pinned(a.shape, dtype=a.dtype)
          cupy.asnumpy(a, out=c, blocking=blocking)
          c[c.size // 2 :] = -1.0  # potential data race
      s.synchronize()
  
      a[c.size // 2 :] = -1.0
      if not blocking:
          ctx = pytest.raises(AssertionError)
      else:
          ctx = contextlib.nullcontext()
      with ctx:
          assert cupy.allclose(a, c)
  
imports: import contextlib
  import unittest
  import numpy
  import pytest
  import cupy
  from cupy import testing
  import cupyx
label_desc: Use image node_id 3 for calling the TestAsnumpy obj's underlying member method code with example usage: obj.test_asnumpy_blocking(blocking) without return types