code: def test_set_keepalive_time(self):
      with self.assertRaises(interfaces.cache.CacheError):
          interfaces.cache.set_keepalive_time(10)
  
      interfaces.cache.enable()
      interfaces.cache.set_keepalive_time(10)
  
      self.assertTrue(
          interfaces.cache._fftw_cache.keepalive_time == 10.0
      )
  
      interfaces.cache.disable()
  
imports: import copy
  import sys
  from pyfftw import interfaces, builders
  import pyfftw
  import numpy
  import numpy
  import unittest
  from .test_pyfftw_base import run_test_suites, miss
  from .test_pyfftw_numpy_interface import InterfacesNumpyFFTTestFFT
  import threading
  import time
  import os
  import hashlib
label_desc: Use image node_id 4 for calling the InterfacesCacheTest obj's underlying member method code with example usage: obj.test_set_keepalive_time() without return types