code: def test_mempool(self):
      from pycuda.tools import bitlog2
      from pycuda.tools import DeviceMemoryPool
  
      pool = DeviceMemoryPool()
      queue = []
      free, total = drv.mem_get_info()
  
      e0 = bitlog2(free)
  
      for e in range(e0 - 6, e0 - 4):
          for i in range(100):
              queue.append(pool.allocate(1 << e))
              if len(queue) > 10:
                  queue.pop(0)
      del queue
      pool.stop_holding()
  
imports: import numpy
  import numpy.linalg
  from pycuda.tools import mark_cuda_test, dtype_to_ctype
  import pytest
  import pycuda.gpuarray
  import pycuda.driver
  from pycuda.compiler import SourceModule
label_desc: Use image node_id 21 for calling the TestDriver obj's underlying member method code with example usage: obj.test_mempool() without return types