title: Testing redis key expiration
body: <p>I was wondering if anyone has a clever way of testing behavior after a redis key expires. I am essentially building a small redis backed cache for my application and would like to test what happens after a redis key is set to expire.</p>
  
  <p>I am using rspec as my testing framework. I tried to use Timecop to change the time during testing but realized that it would only effect the testing frame work and not the external redis server.</p>
  
  <p>I can set the TTL to 1 and then use a sleep(1) but I would rather not introduce sleeps into my tests.</p>
  
  <p>Does anyone have a good way of testing this?</p>