title: clojure.core.cache just does not work using their own example
body: <p>I just added clojure.core.cache 0.6.1 to my project, did a lein deps, followed the very short and clear example here: <a href="https://github.com/clojure/core.cache" rel="noreferrer">https://github.com/clojure/core.cache</a> and it just flat out does not work.</p>
  
  <p>Example:</p>
  
  <pre><code>$lein repl
  REPL started; server listening on localhost port 20513
  user=&gt; (require '[clojure.core.cache :as cache])
  nil
  user=&gt; (def fifoc (cache/fifo-cache-factory {}))
  #'user/fifoc
  user=&gt; (cache/has? fifoc :foo)
  false
  user=&gt; (cache/miss fifoc :foo "bar")
  {:foo "bar"}
  user=&gt; (cache/has? fifoc :foo)
  false
  </code></pre>
  
  <p>What is going wrong here? Am I completely missing the point? I've tried it with the other cache backends all with the same result. Tried it with different keys, different values, different namespace, different alias - nada. Running the tests gives me this:</p>
  
  <pre><code>$ lein test clojure.core.cache.tests
  
  Testing clojure.core.cache.tests
  
  Ran 13 tests containing 273 assertions.
  0 failures, 0 errors.
  </code></pre>
  
  <p>Which makes this all the more mysterious. I looked at the tests, and while they :import the cache backends and instantiate them the java way (miss (BasicCache. {}) ...), which I also tried, that too fails for me in exactly the same way.</p>
  
  <p>Any help before I just implement one that works?</p>