code: def test_hook(self):
      hook = SimpleMemoryHook()
      with cupy.cuda.Device(0):
          with hook:
              mem = self.pool.malloc(1)
              ptr1, pmem1 = (mem.ptr, id(mem.mem))
              del mem
              mem = self.pool.malloc(1)
              ptr2, pmem2 = (mem.ptr, id(mem.mem))
              del mem
      assert 1 == len(hook.alloc_preprocess_history)
      assert 1 == len(hook.alloc_postprocess_history)
      assert 2 == len(hook.malloc_preprocess_history)
      assert 2 == len(hook.malloc_postprocess_history)
      assert 2 == len(hook.free_preprocess_history)
      assert 2 == len(hook.free_postprocess_history)
      assert {
          "device_id": 0,
          "mem_size": self.unit,
      } == hook.alloc_preprocess_history[0]
      assert {
          "device_id": 0,
          "mem_size": self.unit,
          "mem_ptr": ptr1,
      } == hook.alloc_postprocess_history[0]
      assert {
          "device_id": 0,
          "size": 1,
          "mem_size": self.unit,
      } == hook.malloc_preprocess_history[0]
      assert {
          "device_id": 0,
          "size": 1,
          "mem_size": self.unit,
          "mem_ptr": ptr1,
          "pmem_id": pmem1,
      } == hook.malloc_postprocess_history[0]
      assert {
          "device_id": 0,
          "size": 1,
          "mem_size": self.unit,
      } == hook.malloc_preprocess_history[1]
      assert {
          "device_id": 0,
          "size": 1,
          "mem_size": self.unit,
          "mem_ptr": ptr2,
          "pmem_id": pmem2,
      } == hook.malloc_postprocess_history[1]
      assert {
          "device_id": 0,
          "mem_size": self.unit,
          "mem_ptr": ptr1,
          "pmem_id": pmem1,
      } == hook.free_preprocess_history[0]
      assert {
          "device_id": 0,
          "mem_size": self.unit,
          "mem_ptr": ptr1,
          "pmem_id": pmem1,
      } == hook.free_postprocess_history[0]
      assert {
          "device_id": 0,
          "mem_size": self.unit,
          "mem_ptr": ptr2,
          "pmem_id": pmem2,
      } == hook.free_preprocess_history[1]
      assert {
          "device_id": 0,
          "mem_size": self.unit,
          "mem_ptr": ptr2,
          "pmem_id": pmem2,
      } == hook.free_postprocess_history[1]
  
file_path: cupy/tests/cupy_tests/cuda_tests/test_memory_hook.py
imports: import unittest
  import cupy.cuda
  from cupy.cuda import memory
  from cupy.cuda import memory_hook
label_desc: Use image node_id 2 for calling the TestMemoryHook obj's underlying member method code with example usage: obj.test_hook() without return types