code: def test_insert_and_lookup_item(self):
      _cache = interfaces.cache._Cache()
  
      key = "the key"
  
      test_array = numpy.random.randn(16)
      obj = builders.fft(test_array)
      _cache.insert(obj, key)
  
      self.assertIs(_cache.lookup(key), obj)
  
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 3 for calling the CacheTest obj's underlying member method code with example usage: obj.test_insert_and_lookup_item() without return types