code: def test_deleter(self):
      # memory is freed when tensor is deleted, as it's not consumed
      array = cupy.empty(10)
      tensor = array.toDlpack()
      # str(tensor): <capsule object "dltensor" at 0x7f7c4c835330>
      assert '"dltensor"' in str(tensor)
      assert self.pool.n_free_blocks() == 0
      del array
      assert self.pool.n_free_blocks() == 0
      del tensor
      assert self.pool.n_free_blocks() == 1
  
imports: import unittest
  import pytest
  import cupy
  from cupy import cuda
  from cupy import testing
label_desc: Use image node_id 3 for calling the TestDLTensorMemory obj's underlying member method code with example usage: obj.test_deleter() without return types