make the test not leak memory so much
make the test not leak memory so much

emilybache/Device-Driver-Kata,emilybache/Device-Driver-Kata,emilybache/Device-Driver-Kata,emilybache/Device-Driver-Kata,emilybache/Device-Driver-Kata,emilybache/Device-Driver-Kata,emilybache/Device-Driver-Kata,emilybache/Device-Driver-Kata,emilybache/Device-Driver-Kata,emilybache/Device-Driver-Kata